This document provides an overview of Monero, a cryptocurrency focused on privacy and decentralization. It discusses Monero's use of ring signatures and ring confidential transactions to obscure sender, recipient, and transaction amounts. It also covers Monero's development history and ongoing work to improve usability, compliance, and the community.
Monero Presentation by Justin Ehrenhofer - Cologne, Germany 2017Justin Ehrenhofer
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Monero is a cryptocurrency that focuses on privacy and fungibility. It uses ring signatures, stealth addresses, and ring confidential transactions (RingCT) to obscure transaction metadata. Ring signatures make it impossible to link inputs and outputs of a transaction. Stealth addresses hide recipient information. RingCT hides transaction amounts. Monero is undergoing ongoing development to improve its privacy and usability, with a planned hardfork in September to make RingCT mandatory. Its community and adoption have grown substantially in recent years.
Monero Presentation by Justin Ehrenhofer - Rome, Italy 2017Justin Ehrenhofer
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This document introduces Monero, a cryptocurrency that focuses on privacy and anonymity. It summarizes Monero's key features as:
1) Using ring signatures and Ring Confidential Transactions (RingCT) to obscure the origin, amounts, and destinations of transactions.
2) Implementing stealth addresses to hide receiving addresses and amounts.
3) Making privacy the default by making all transactions private starting in March 2016.
4) Continuing development to improve privacy, usability, and compliance through features like view keys, sub-addresses, and lightweight wallets.
Monero Presentation by Justin Ehrenhofer - Stockholm, Sweden 2017Justin Ehrenhofer
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Monero is a cryptocurrency that focuses on privacy and anonymity. It uses ring signatures and ring confidential transactions (RingCT) to obscure transaction amounts and the origin of funds. Ring signatures group transactions together so the real input is indistinguishable among others in the group. RingCT further hides transaction amounts using Pedersen commitments. Monero also uses stealth addresses to mask the recipient and Kovri to further anonymize IP addresses. Upcoming upgrades will increase the minimum ring size and implement other improvements to enhance privacy and usability.
Monero Presentation by Justin Ehrenhofer - Helsinki, Finland 2017Justin Ehrenhofer
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Monero is a cryptocurrency that focuses on privacy and fungibility. It uses ring signatures and ring confidential transactions (RingCT) to obscure transaction amounts and the origin of funds. Ring signatures mix the real spender's key with others, making it impossible to tell which key was used. RingCT hides amounts and allows only the recipient to see the transaction amount. Upcoming upgrades will increase the minimum ring size and implement other improvements. Monero development prioritizes privacy, security, and decentralization through ongoing upgrades to its protocol.
Monero Presentation by Justin Ehrenhofer - Brussels, Belguim 2017Justin Ehrenhofer
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Monero is a cryptocurrency that focuses on privacy and anonymity. It uses ring signatures and ring confidential transactions (RingCT) to obscure transaction amounts and the origin of funds. Ring signatures group transactions together so the real input is indistinguishable among others. RingCT further hides amounts through commitments. Stealth addresses receive payments privately. Monero development aims to improve usability and compliance while maintaining strong privacy through techniques like view keys and sub-addresses.
Monero Presentation by Justin Ehrenhofer - Barcelona, Spain 2017Justin Ehrenhofer
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Monero is a cryptocurrency that focuses on privacy and fungibility. It uses ring signatures, stealth addresses, and ring confidential transactions (RingCT) to obscure transaction metadata. Ring signatures make it impossible to link inputs and outputs of a transaction. Stealth addresses hide recipient information. RingCT hides transaction amounts. Monero is undergoing ongoing development to improve its privacy and usability, with a planned hard fork in September to make RingCT mandatory.
Monero Presentation by Justin Ehrenhofer - Oslo, Norway 2017Justin Ehrenhofer
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Ring signatures and ring confidential transactions (RingCT) help provide privacy and security in Monero transactions. Transactions include dummy outputs which make it difficult to determine real inputs and outputs, providing privacy. Stealth addresses further obscure sender and recipient identities. Monero aims to provide untraceable and private transactions by default through these techniques.
Monero Presentation by Justin Ehrenhofer - Copenhagen, Denmark 2017Justin Ehrenhofer
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Monero is a cryptocurrency that focuses on privacy and anonymity. It uses ring signatures to hide the origin and destination of transactions, and ring confidential transactions to conceal amounts. Monero development includes ongoing work to improve privacy through techniques like larger minimum ring sizes, improved input selection algorithms, and integration with networks like I2P. The Monero community is also growing to support further development and adoption of the currency.
Monero Presentation by Justin Ehrenhofer - Cologne, Germany 2017Justin Ehrenhofer
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Monero is a cryptocurrency that focuses on privacy and fungibility. It uses ring signatures, stealth addresses, and ring confidential transactions (RingCT) to obscure transaction metadata. Ring signatures make it impossible to link inputs and outputs of a transaction. Stealth addresses hide recipient information. RingCT hides transaction amounts. Monero is undergoing ongoing development to improve its privacy and usability, with a planned hardfork in September to make RingCT mandatory. Its community and adoption have grown substantially in recent years.
Monero Presentation by Justin Ehrenhofer - Rome, Italy 2017Justin Ehrenhofer
Â
This document introduces Monero, a cryptocurrency that focuses on privacy and anonymity. It summarizes Monero's key features as:
1) Using ring signatures and Ring Confidential Transactions (RingCT) to obscure the origin, amounts, and destinations of transactions.
2) Implementing stealth addresses to hide receiving addresses and amounts.
3) Making privacy the default by making all transactions private starting in March 2016.
4) Continuing development to improve privacy, usability, and compliance through features like view keys, sub-addresses, and lightweight wallets.
Monero Presentation by Justin Ehrenhofer - Stockholm, Sweden 2017Justin Ehrenhofer
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Monero is a cryptocurrency that focuses on privacy and anonymity. It uses ring signatures and ring confidential transactions (RingCT) to obscure transaction amounts and the origin of funds. Ring signatures group transactions together so the real input is indistinguishable among others in the group. RingCT further hides transaction amounts using Pedersen commitments. Monero also uses stealth addresses to mask the recipient and Kovri to further anonymize IP addresses. Upcoming upgrades will increase the minimum ring size and implement other improvements to enhance privacy and usability.
Monero Presentation by Justin Ehrenhofer - Helsinki, Finland 2017Justin Ehrenhofer
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Monero is a cryptocurrency that focuses on privacy and fungibility. It uses ring signatures and ring confidential transactions (RingCT) to obscure transaction amounts and the origin of funds. Ring signatures mix the real spender's key with others, making it impossible to tell which key was used. RingCT hides amounts and allows only the recipient to see the transaction amount. Upcoming upgrades will increase the minimum ring size and implement other improvements. Monero development prioritizes privacy, security, and decentralization through ongoing upgrades to its protocol.
Monero Presentation by Justin Ehrenhofer - Brussels, Belguim 2017Justin Ehrenhofer
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Monero is a cryptocurrency that focuses on privacy and anonymity. It uses ring signatures and ring confidential transactions (RingCT) to obscure transaction amounts and the origin of funds. Ring signatures group transactions together so the real input is indistinguishable among others. RingCT further hides amounts through commitments. Stealth addresses receive payments privately. Monero development aims to improve usability and compliance while maintaining strong privacy through techniques like view keys and sub-addresses.
Monero Presentation by Justin Ehrenhofer - Barcelona, Spain 2017Justin Ehrenhofer
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Monero is a cryptocurrency that focuses on privacy and fungibility. It uses ring signatures, stealth addresses, and ring confidential transactions (RingCT) to obscure transaction metadata. Ring signatures make it impossible to link inputs and outputs of a transaction. Stealth addresses hide recipient information. RingCT hides transaction amounts. Monero is undergoing ongoing development to improve its privacy and usability, with a planned hard fork in September to make RingCT mandatory.
Monero Presentation by Justin Ehrenhofer - Oslo, Norway 2017Justin Ehrenhofer
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Ring signatures and ring confidential transactions (RingCT) help provide privacy and security in Monero transactions. Transactions include dummy outputs which make it difficult to determine real inputs and outputs, providing privacy. Stealth addresses further obscure sender and recipient identities. Monero aims to provide untraceable and private transactions by default through these techniques.
Monero Presentation by Justin Ehrenhofer - Copenhagen, Denmark 2017Justin Ehrenhofer
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Monero is a cryptocurrency that focuses on privacy and anonymity. It uses ring signatures to hide the origin and destination of transactions, and ring confidential transactions to conceal amounts. Monero development includes ongoing work to improve privacy through techniques like larger minimum ring sizes, improved input selection algorithms, and integration with networks like I2P. The Monero community is also growing to support further development and adoption of the currency.
Monero is a cryptocurrency that focuses on privacy and fungibility. It uses ring signatures and ring confidential transactions (RingCT) to obscure transaction amounts and the origin of funds. Ring signatures mix the real spender's key with other keys to make it impossible to tell which key was used. RingCT hides amounts by using Pedersen commitments. Monero also uses stealth addresses to hide recipient addresses. Future developments aim to further improve privacy with larger ring sizes and reduce transaction sizes with techniques like bulletproofs. The Monero community and ecosystem continue growing with services like XMR.TO and more merchants accepting Monero.
Monero Presentation by Justin Ehrenhofer - Vienna, Austria 2017Justin Ehrenhofer
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This document summarizes Monero, a cryptocurrency focused on privacy and anonymity. It discusses how Monero uses ring signatures and ring confidential transactions to obscure sender, recipient, and transaction amounts. It also explains other privacy features like stealth addresses and optional view keys that allow selective transparency. The summary highlights Monero's ongoing development work to improve usability, compliance, and scalability through initiatives like multisig addresses, lightweight wallets, and scheduled hardforks.
Monero Presentation by Justin Ehrenhofer - Athens, Greece 2017Justin Ehrenhofer
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This document summarizes Monero, a cryptocurrency that focuses on privacy and anonymity. It discusses how Monero uses ring signatures and ring confidential transactions (RingCT) to obscure transaction amounts and the origin of funds. It also covers Monero's history and ongoing development, including making privacy mandatory in 2016, the addition of RingCT in 2017, and planned hardforks to improve privacy and scalability. Regulatory compliance features like view keys are also summarized that allow selective transparency of transactions for entities like charities or parents.
Monero Presentation by Justin Ehrenhofer - Budapest, Hungary 2017Justin Ehrenhofer
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This document summarizes key features of the cryptocurrency Monero including its focus on privacy, anonymity and untraceability. It discusses tools like ring signatures and ring confidential transactions that obscure transaction amounts and participant identities on the blockchain. It also notes some limitations around transaction size but outlines ongoing development work and an upcoming hardfork to address privacy and scaling.
Monero Presentation by Justin Ehrenhofer - Warsaw, Poland 2017Justin Ehrenhofer
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This document summarizes key aspects of the cryptocurrency Monero including its privacy features like ring signatures and ring confidential transactions. It explains how Monero transactions work compared to Bitcoin by obscuring sender, recipient, and amount through these techniques. The document also covers some limitations of Monero and ongoing development work to improve areas like transaction size and integration of new features.
Roy Wasse is a Dutch JUG leader and co-founder of OpenValue who is interested in technological change. The document discusses various cryptographic techniques including the one-time pad encryption method, stream ciphers, hashing versus encryption, block ciphers, asymmetric encryption using elliptic curves, quantum key distribution, and various applications like mixing services and onion routing for anonymity. It also touches on concepts like commitment schemes, zero-knowledge proofs, scriptless transactions in Mimblewimble, and using digital signatures to unlock content.
Monero Presentation by Justin Ehrenhofer - Wroclaw, Poland 2017Justin Ehrenhofer
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This document summarizes key features of the Monero cryptocurrency including its focus on privacy and fungibility. Monero uses ring signatures, ring confidential transactions (RingCT), and stealth addresses to obscure the origin, amounts, and destinations of transactions. It has undergone mandatory privacy upgrades and aims to provide full regulatory compliance through optional view keys while maintaining user privacy. Ongoing development seeks to improve scalability and usability.
Python uses the Global Interpreter Lock (GIL) which allows only one thread to hold the lock for a Python interpreter at any one time. This can limit performance in CPU-bound multithreaded applications. The GIL is released for I/O-bound operations to allow other threads to run while waiting for I/O to complete. It exists to simplify the CPython implementation but can reduce parallelism, so workarounds like multiprocessing are used for truly multithreaded tasks. There is ongoing discussion on completely removing the GIL but it would require significant changes to the Python interpreter.
This document provides a ranking of 89 clans based on their performance in a game. It lists each clan's name, number of games played, number of wins, losses, and total points. The clans are ranked from 1st to 89th place based on their total points.
Evaluating Private Cryptocurrency Technologies and ImplementationsJustin Ehrenhofer
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This document summarizes Justin Ehrenhofer's presentation on evaluating private technologies and implementations. The key points are:
1. Justin introduces himself and his background in cybersecurity and interest in distributed privacy systems.
2. The document discusses how privacy is not a binary concept and examines different threat models and implications of transparency versus privacy.
3. It provides an overview of how Monero aims to increase privacy through techniques like ring signatures, ring confidential transactions, stealth addresses and other methods, while acknowledging limitations.
4. The presentation emphasizes that privacy solutions should be evaluated based on both theoretical privacy and practical usability factors, and that no system provides perfect privacy due to limitations like metadata leaks and potential attack vectors
The document discusses blockchain and cryptocurrency technologies. It provides information on the following key points:
- Cryptographic hash functions are the backbone of blockchain and map variable-length inputs to fixed-length outputs, making it difficult to determine the input from the output or find colliding inputs.
- Blockchain uses these hash functions to create tamper-evident linked data structures like blocks in a blockchain or nodes in a Merkle tree. This allows transactions in a blockchain to be publicly verifiable and tamper-resistant.
- Bitcoin implements blockchain technology to create a decentralized transaction ledger. Transactions are grouped into blocks and miners compete to add new blocks through a computational puzzle. This consensus mechanism allows all nodes to agree
Delivered at Casual Connect USA 2018. A big trading firm announced that its average hold time on a stock was 11 seconds. If this is considered investing, why do many say this sounds like betting and vice versa? On-the-fly wagering while the game unfolds, known as in-running, is new to casinos. How can blockchain and in-game wallets provide a system that is robust enough to handle the play-by-play handicapping, where the game is the market?
“Technical Intro to Blockhain” by Yurijs Pimenovs from Paybis at CryptoCurren...Dace Barone
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He will give an introduction talk about Blockchain technology technical aspects like cryptography, protocols, APIs and scripting with focus on explaining how Bitcoin and other blockchain works and what they consist of.
Yurijs is a Chief Technical Officer at Paybis, blogger at coinside.ru , blockchain enthusiast since 2011.
Monero Presentation by Justin Ehrenhofer - Zagreb, Croatia 2017Justin Ehrenhofer
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This document provides information about financial privacy and the cryptocurrency Monero. It begins with statistics on how sensitive people view different types of personal information. It then discusses concepts like fungibility and the history of privacy in Bitcoin. The document outlines tools that were added to Bitcoin to improve privacy as well as the technical differences in Monero including ring signatures, stealth addresses, and ring confidential transactions that help provide privacy and fungibility. It also notes ongoing development areas in Monero and its roadmap to further improve privacy and scalability.
Defcon Monero Ring Signatures Presentation by Justin Ehrenhofer 2018Justin Ehrenhofer
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This document discusses ring signatures in Monero and some of the challenges related to increasing the ring size. It covers how ring signatures are intended to provide plausible deniability but certain attacks can reduce that deniability. These include 0-decoy attacks, chain reaction attacks, and key image reuse on chain splits. The document recommends best practices like blacklisting compromised outputs and churning to help maintain anonymity. It also notes increasing the ring size faces technical challenges related to blockchain size and computation costs.
This document discusses cryptocurrency privacy implementations for Bitcoin and Dash. It describes CoinJoin, a technique used by JoinMarket to conduct mixing of Bitcoin transactions on the blockchain in a peer-to-peer manner. It also describes masternode mixing for Dash, which performs mixing of transactions ahead of time through masternodes. The document provides steps to set up a JoinMarket wallet, fund it, and conduct mixing by joining the peer-to-peer CoinJoin market and sending payments between different mixing depths.
201803 Blockchains, Cryptocurrencies & Tokens - NYC Bar Association Presentat...Paperchain
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Presented at the NYC Bar Association, an overview of the technologies that make up blockchain technology and why those technologies have implications with existing legal frameworks.
Bitcoin : A fierce Decentralized internet currencyShivek Khurana
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- Bitcoin is a decentralized cryptocurrency that uses blockchain technology to enable peer-to-peer transactions without intermediaries like banks. It was created in 2008 by the anonymous person or group known as Satoshi Nakamoto.
- The Bitcoin protocol uses digital signatures, hashing, and a proof-of-work system where miners validate transactions and are rewarded with new bitcoins. Transactions are grouped into blocks that are added to the blockchain in a decentralized manner.
- Bitcoin allows for low-cost or free global transactions, with no banks or transaction limits, providing an alternative payment method outside the traditional banking system. However, understanding the technical details of the Bitcoin protocol requires knowledge of cryptography, digital architecture, and other technical fields
This demand for implementing the most common Transactions,Pay to PubKey Hash,Pay to PubKey,Pay to Script Hash,Multi-Signature and Null Data stemed from the need to have a closer look of how Bitcoin Transactions work in the context of my thesis as an undergraduate student of Department of Applied Informatics at the University of Macedonia,Greece.
This document outlines a bachelor's thesis project that aims to analyze and program basic transactions of the Bitcoin system. The project will analyze how transaction scripts are executed in the Bitcoin stack and program basic transaction types like pay-to-public-key-hash using the BitcoinJ Java library. The document provides background on Bitcoin technology, including how elliptic curve keys and digital signatures are used to create transactions. It also describes the anatomy of Bitcoin transactions and how different scripting applications like escrow and micropayments work.
Monero is a cryptocurrency that focuses on privacy and fungibility. It uses ring signatures and ring confidential transactions (RingCT) to obscure transaction amounts and the origin of funds. Ring signatures mix the real spender's key with other keys to make it impossible to tell which key was used. RingCT hides amounts by using Pedersen commitments. Monero also uses stealth addresses to hide recipient addresses. Future developments aim to further improve privacy with larger ring sizes and reduce transaction sizes with techniques like bulletproofs. The Monero community and ecosystem continue growing with services like XMR.TO and more merchants accepting Monero.
Monero Presentation by Justin Ehrenhofer - Vienna, Austria 2017Justin Ehrenhofer
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This document summarizes Monero, a cryptocurrency focused on privacy and anonymity. It discusses how Monero uses ring signatures and ring confidential transactions to obscure sender, recipient, and transaction amounts. It also explains other privacy features like stealth addresses and optional view keys that allow selective transparency. The summary highlights Monero's ongoing development work to improve usability, compliance, and scalability through initiatives like multisig addresses, lightweight wallets, and scheduled hardforks.
Monero Presentation by Justin Ehrenhofer - Athens, Greece 2017Justin Ehrenhofer
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This document summarizes Monero, a cryptocurrency that focuses on privacy and anonymity. It discusses how Monero uses ring signatures and ring confidential transactions (RingCT) to obscure transaction amounts and the origin of funds. It also covers Monero's history and ongoing development, including making privacy mandatory in 2016, the addition of RingCT in 2017, and planned hardforks to improve privacy and scalability. Regulatory compliance features like view keys are also summarized that allow selective transparency of transactions for entities like charities or parents.
Monero Presentation by Justin Ehrenhofer - Budapest, Hungary 2017Justin Ehrenhofer
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This document summarizes key features of the cryptocurrency Monero including its focus on privacy, anonymity and untraceability. It discusses tools like ring signatures and ring confidential transactions that obscure transaction amounts and participant identities on the blockchain. It also notes some limitations around transaction size but outlines ongoing development work and an upcoming hardfork to address privacy and scaling.
Monero Presentation by Justin Ehrenhofer - Warsaw, Poland 2017Justin Ehrenhofer
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This document summarizes key aspects of the cryptocurrency Monero including its privacy features like ring signatures and ring confidential transactions. It explains how Monero transactions work compared to Bitcoin by obscuring sender, recipient, and amount through these techniques. The document also covers some limitations of Monero and ongoing development work to improve areas like transaction size and integration of new features.
Roy Wasse is a Dutch JUG leader and co-founder of OpenValue who is interested in technological change. The document discusses various cryptographic techniques including the one-time pad encryption method, stream ciphers, hashing versus encryption, block ciphers, asymmetric encryption using elliptic curves, quantum key distribution, and various applications like mixing services and onion routing for anonymity. It also touches on concepts like commitment schemes, zero-knowledge proofs, scriptless transactions in Mimblewimble, and using digital signatures to unlock content.
Monero Presentation by Justin Ehrenhofer - Wroclaw, Poland 2017Justin Ehrenhofer
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This document summarizes key features of the Monero cryptocurrency including its focus on privacy and fungibility. Monero uses ring signatures, ring confidential transactions (RingCT), and stealth addresses to obscure the origin, amounts, and destinations of transactions. It has undergone mandatory privacy upgrades and aims to provide full regulatory compliance through optional view keys while maintaining user privacy. Ongoing development seeks to improve scalability and usability.
Python uses the Global Interpreter Lock (GIL) which allows only one thread to hold the lock for a Python interpreter at any one time. This can limit performance in CPU-bound multithreaded applications. The GIL is released for I/O-bound operations to allow other threads to run while waiting for I/O to complete. It exists to simplify the CPython implementation but can reduce parallelism, so workarounds like multiprocessing are used for truly multithreaded tasks. There is ongoing discussion on completely removing the GIL but it would require significant changes to the Python interpreter.
This document provides a ranking of 89 clans based on their performance in a game. It lists each clan's name, number of games played, number of wins, losses, and total points. The clans are ranked from 1st to 89th place based on their total points.
Evaluating Private Cryptocurrency Technologies and ImplementationsJustin Ehrenhofer
Â
This document summarizes Justin Ehrenhofer's presentation on evaluating private technologies and implementations. The key points are:
1. Justin introduces himself and his background in cybersecurity and interest in distributed privacy systems.
2. The document discusses how privacy is not a binary concept and examines different threat models and implications of transparency versus privacy.
3. It provides an overview of how Monero aims to increase privacy through techniques like ring signatures, ring confidential transactions, stealth addresses and other methods, while acknowledging limitations.
4. The presentation emphasizes that privacy solutions should be evaluated based on both theoretical privacy and practical usability factors, and that no system provides perfect privacy due to limitations like metadata leaks and potential attack vectors
The document discusses blockchain and cryptocurrency technologies. It provides information on the following key points:
- Cryptographic hash functions are the backbone of blockchain and map variable-length inputs to fixed-length outputs, making it difficult to determine the input from the output or find colliding inputs.
- Blockchain uses these hash functions to create tamper-evident linked data structures like blocks in a blockchain or nodes in a Merkle tree. This allows transactions in a blockchain to be publicly verifiable and tamper-resistant.
- Bitcoin implements blockchain technology to create a decentralized transaction ledger. Transactions are grouped into blocks and miners compete to add new blocks through a computational puzzle. This consensus mechanism allows all nodes to agree
Delivered at Casual Connect USA 2018. A big trading firm announced that its average hold time on a stock was 11 seconds. If this is considered investing, why do many say this sounds like betting and vice versa? On-the-fly wagering while the game unfolds, known as in-running, is new to casinos. How can blockchain and in-game wallets provide a system that is robust enough to handle the play-by-play handicapping, where the game is the market?
“Technical Intro to Blockhain” by Yurijs Pimenovs from Paybis at CryptoCurren...Dace Barone
Â
He will give an introduction talk about Blockchain technology technical aspects like cryptography, protocols, APIs and scripting with focus on explaining how Bitcoin and other blockchain works and what they consist of.
Yurijs is a Chief Technical Officer at Paybis, blogger at coinside.ru , blockchain enthusiast since 2011.
Monero Presentation by Justin Ehrenhofer - Zagreb, Croatia 2017Justin Ehrenhofer
Â
This document provides information about financial privacy and the cryptocurrency Monero. It begins with statistics on how sensitive people view different types of personal information. It then discusses concepts like fungibility and the history of privacy in Bitcoin. The document outlines tools that were added to Bitcoin to improve privacy as well as the technical differences in Monero including ring signatures, stealth addresses, and ring confidential transactions that help provide privacy and fungibility. It also notes ongoing development areas in Monero and its roadmap to further improve privacy and scalability.
Defcon Monero Ring Signatures Presentation by Justin Ehrenhofer 2018Justin Ehrenhofer
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This document discusses ring signatures in Monero and some of the challenges related to increasing the ring size. It covers how ring signatures are intended to provide plausible deniability but certain attacks can reduce that deniability. These include 0-decoy attacks, chain reaction attacks, and key image reuse on chain splits. The document recommends best practices like blacklisting compromised outputs and churning to help maintain anonymity. It also notes increasing the ring size faces technical challenges related to blockchain size and computation costs.
This document discusses cryptocurrency privacy implementations for Bitcoin and Dash. It describes CoinJoin, a technique used by JoinMarket to conduct mixing of Bitcoin transactions on the blockchain in a peer-to-peer manner. It also describes masternode mixing for Dash, which performs mixing of transactions ahead of time through masternodes. The document provides steps to set up a JoinMarket wallet, fund it, and conduct mixing by joining the peer-to-peer CoinJoin market and sending payments between different mixing depths.
201803 Blockchains, Cryptocurrencies & Tokens - NYC Bar Association Presentat...Paperchain
Â
Presented at the NYC Bar Association, an overview of the technologies that make up blockchain technology and why those technologies have implications with existing legal frameworks.
Bitcoin : A fierce Decentralized internet currencyShivek Khurana
Â
- Bitcoin is a decentralized cryptocurrency that uses blockchain technology to enable peer-to-peer transactions without intermediaries like banks. It was created in 2008 by the anonymous person or group known as Satoshi Nakamoto.
- The Bitcoin protocol uses digital signatures, hashing, and a proof-of-work system where miners validate transactions and are rewarded with new bitcoins. Transactions are grouped into blocks that are added to the blockchain in a decentralized manner.
- Bitcoin allows for low-cost or free global transactions, with no banks or transaction limits, providing an alternative payment method outside the traditional banking system. However, understanding the technical details of the Bitcoin protocol requires knowledge of cryptography, digital architecture, and other technical fields
This demand for implementing the most common Transactions,Pay to PubKey Hash,Pay to PubKey,Pay to Script Hash,Multi-Signature and Null Data stemed from the need to have a closer look of how Bitcoin Transactions work in the context of my thesis as an undergraduate student of Department of Applied Informatics at the University of Macedonia,Greece.
This document outlines a bachelor's thesis project that aims to analyze and program basic transactions of the Bitcoin system. The project will analyze how transaction scripts are executed in the Bitcoin stack and program basic transaction types like pay-to-public-key-hash using the BitcoinJ Java library. The document provides background on Bitcoin technology, including how elliptic curve keys and digital signatures are used to create transactions. It also describes the anatomy of Bitcoin transactions and how different scripting applications like escrow and micropayments work.
A simplified Bitcoin Implementation in GOBrian Yap
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This document describes a simplified cryptocurrency called Scrooge Coin and how transactions work within that system. It defines transactions as having inputs and outputs like a double-entry ledger. The inputs reference previous transaction outputs and include a signature to prove ownership. It then provides sample transaction code and discusses how transactions are verified by checking things like valid signatures, preventing double spending of outputs, and maintaining the balance of inputs and outputs.
During the last two years we have being working hard on the new hype: Blockchain.
In this talk we will guide you through this new world alongside with the most remarkable contributions we have done so far on the domain, passing by the contract inspector, the ukulele query language, the metric analysis and more.
What is a decentralised application ? - Les Jeudis du LibreWajug
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A decentralized application (DApp) is an application that runs on a decentralized network like Ethereum rather than being hosted and controlled by a single company. A DApp uses blockchain technology and smart contracts to allow peer-to-peer transactions and decisions without an intermediary. Ethereum allows developers to create DApps with Turing-complete smart contracts that can automate processes and disintermediate industries like banking, insurance, and more. DApps are accessed through a web interface or mobile app and interact with smart contracts deployed on the Ethereum blockchain.
Post-Bitcoin Cryptocurrencies, Off-Chain Transaction Channels, and Cryptocur...Bernhard Haslhofer
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The document provides an overview of post-Bitcoin cryptocurrencies, off-chain transaction channels, and cryptocurrency analytics techniques. It discusses the realities of Bitcoin compared to initial promises and expectations, such as de-facto centralization and lack of anonymity. Privacy-enhancing cryptocurrencies like Monero and Zcash are introduced that aim to provide untraceable and unlinkable transactions. Off-chain payment channels like the Lightning Network are described as a solution to Bitcoin's scalability problems by moving transactions off-chain. The document concludes by outlining goals and approaches for cryptocurrency analytics to better understand the structure and dynamics of cryptocurrency ecosystems.
What is a decentralised application? - Devoxx Morocco 2018Wajug
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A decentralized application (DApp) is an application that runs on a decentralized peer-to-peer network rather than a central server. The document discusses the evolution of blockchain technology from Bitcoin to Ethereum, which allows for more complex decentralized applications through smart contracts and a Turing-complete programming language. It also covers key concepts like mining, consensus algorithms, and how DApps interact with smart contracts on the Ethereum blockchain through web3.js.
This document provides an overview of cryptography concepts including:
- Cryptography involves encrypting plaintext into ciphertext and decrypting ciphertext back to plaintext using cryptographic algorithms and keys.
- Symmetric key cryptography uses the same key for encryption and decryption while public key cryptography uses separate public and private keys.
- Stream ciphers generate a random keystream to encrypt plaintext bit-by-bit while block ciphers encrypt plaintext blocks using a codebook determined by the cipher key.
- The A5/1 stream cipher was used in GSM systems and works by XORing bits from three shift registers to generate the keystream.
This document provides an overview of cryptography concepts including:
- Cryptography involves encrypting plaintext into ciphertext and decrypting ciphertext back to plaintext using cryptographic algorithms and keys.
- Symmetric key cryptography uses the same key for encryption and decryption while public key cryptography uses separate public and private keys.
- Stream ciphers generate a random keystream to encrypt plaintext bit-by-bit while block ciphers use a codebook to encrypt blocks of plaintext.
- The A5/1 stream cipher was used in GSM and works by XORing bits from three shift registers to generate the keystream.
This document provides an overview of cryptography concepts including:
- Cryptography involves encrypting plaintext into ciphertext and decrypting ciphertext back to plaintext using cryptographic algorithms and keys.
- Symmetric key cryptography uses the same key for encryption and decryption while public key cryptography uses separate public and private keys.
- Stream ciphers generate a random keystream to encrypt plaintext bit-by-bit while block ciphers use a codebook to encrypt blocks of plaintext.
- The A5/1 stream cipher was used in GSM and works by shifting bits in three registers and XORing the output to generate the keystream.
Similar to Monero Presentation by Justin Ehrenhofer - Milwaukee, Wisconsin 2017 (20)
Importance of Privacy in Distributed Systems - NDSUJustin Ehrenhofer
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This document discusses the importance of privacy in distributed systems. It begins with an introduction of the presenter, Justin Ehrenhofer, and his background in cybersecurity and privacy-focused distributed systems. It then discusses how privacy is commonly misunderstood as binary but is actually a constant balancing act between privacy and transparency. The document examines the implications of transparency on individuals and businesses. It also evaluates different tools used to enhance privacy in transparent systems like mixers and zero-knowledge proofs, noting their limitations. The document advocates for privacy solutions like Monero that use ring signatures and ring confidential transactions to increase privacy and fungibility. It acknowledges that even mandatory privacy is not perfect but discusses steps Monero has taken to strengthen privacy.
The document discusses using points of information and outputs to perform a statistical test, with more points of information and outputs higher up providing a better statistical test. The document contains letters, numbers and symbols with no other context.
Monero Presentation by Justin Ehrenhofer - New York City, New York 2019Justin Ehrenhofer
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This document provides an overview of Monero, a cryptocurrency focused on privacy and fungibility. It discusses key concepts like ring signatures and RingCT that provide privacy in Monero transactions. It notes the limitations of transparency in other cryptocurrencies and outlines some of the privacy tools that can be added, but with complications. The document compares Monero to other cryptocurrencies in terms of privacy protections for things like sender, receiver, amount. It also discusses stealth addresses, ring signatures, and RingCT techniques used in Monero to obscure transaction metadata and provide privacy.
Monero Presentation by Justin Ehrenhofer - Valencia, Spain 2017Justin Ehrenhofer
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This document discusses privacy and the evolution of privacy tools for cryptocurrencies like Bitcoin. It focuses on explaining key privacy features of Monero such as ring signatures, ring confidential transactions, stealth addresses, and other tools that provide untraceable transactions. The summary highlights how Monero improved upon Bitcoin's privacy by making all transactions private by default and introducing new technical features over time to strengthen privacy.
Monero Presentation by Justin Ehrenhofer - Riga, Latvia 2017Justin Ehrenhofer
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This document provides an overview of Monero, a cryptocurrency focused on privacy and fungibility. It summarizes Monero's key technical features like ring signatures, ring confidential transactions, and stealth addresses that together provide privacy and anonymity for transactions. It also discusses Monero's ongoing development work to improve scalability and usability while maintaining a high level of privacy.
Monero Presentation by Justin Ehrenhofer - Graz, Austria 2017Justin Ehrenhofer
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Graz, Austria
Welcomes Justin Ehrenhofer for a presentation on why privacy matters in cryptocurrencies like Monero. The document discusses how privacy is important to prevent targeted crime, unintended leaks of personal information, and censorship. It also summarizes that while people say they care about privacy, survey data shows many are willing to share sensitive personal details. The rest of the document outlines Monero's technical approach to privacy through techniques like ring signatures and ring confidential transactions.
Dive into the realm of operating systems (OS) with Pravash Chandra Das, a seasoned Digital Forensic Analyst, as your guide. 🚀 This comprehensive presentation illuminates the core concepts, types, and evolution of OS, essential for understanding modern computing landscapes.
Beginning with the foundational definition, Das clarifies the pivotal role of OS as system software orchestrating hardware resources, software applications, and user interactions. Through succinct descriptions, he delineates the diverse types of OS, from single-user, single-task environments like early MS-DOS iterations, to multi-user, multi-tasking systems exemplified by modern Linux distributions.
Crucial components like the kernel and shell are dissected, highlighting their indispensable functions in resource management and user interface interaction. Das elucidates how the kernel acts as the central nervous system, orchestrating process scheduling, memory allocation, and device management. Meanwhile, the shell serves as the gateway for user commands, bridging the gap between human input and machine execution. đź’»
The narrative then shifts to a captivating exploration of prominent desktop OSs, Windows, macOS, and Linux. Windows, with its globally ubiquitous presence and user-friendly interface, emerges as a cornerstone in personal computing history. macOS, lauded for its sleek design and seamless integration with Apple's ecosystem, stands as a beacon of stability and creativity. Linux, an open-source marvel, offers unparalleled flexibility and security, revolutionizing the computing landscape. 🖥️
Moving to the realm of mobile devices, Das unravels the dominance of Android and iOS. Android's open-source ethos fosters a vibrant ecosystem of customization and innovation, while iOS boasts a seamless user experience and robust security infrastructure. Meanwhile, discontinued platforms like Symbian and Palm OS evoke nostalgia for their pioneering roles in the smartphone revolution.
The journey concludes with a reflection on the ever-evolving landscape of OS, underscored by the emergence of real-time operating systems (RTOS) and the persistent quest for innovation and efficiency. As technology continues to shape our world, understanding the foundations and evolution of operating systems remains paramount. Join Pravash Chandra Das on this illuminating journey through the heart of computing. 🌟
5th LF Energy Power Grid Model Meet-up SlidesDanBrown980551
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5th Power Grid Model Meet-up
It is with great pleasure that we extend to you an invitation to the 5th Power Grid Model Meet-up, scheduled for 6th June 2024. This event will adopt a hybrid format, allowing participants to join us either through an online Mircosoft Teams session or in person at TU/e located at Den Dolech 2, Eindhoven, Netherlands. The meet-up will be hosted by Eindhoven University of Technology (TU/e), a research university specializing in engineering science & technology.
Power Grid Model
The global energy transition is placing new and unprecedented demands on Distribution System Operators (DSOs). Alongside upgrades to grid capacity, processes such as digitization, capacity optimization, and congestion management are becoming vital for delivering reliable services.
Power Grid Model is an open source project from Linux Foundation Energy and provides a calculation engine that is increasingly essential for DSOs. It offers a standards-based foundation enabling real-time power systems analysis, simulations of electrical power grids, and sophisticated what-if analysis. In addition, it enables in-depth studies and analysis of the electrical power grid’s behavior and performance. This comprehensive model incorporates essential factors such as power generation capacity, electrical losses, voltage levels, power flows, and system stability.
Power Grid Model is currently being applied in a wide variety of use cases, including grid planning, expansion, reliability, and congestion studies. It can also help in analyzing the impact of renewable energy integration, assessing the effects of disturbances or faults, and developing strategies for grid control and optimization.
What to expect
For the upcoming meetup we are organizing, we have an exciting lineup of activities planned:
-Insightful presentations covering two practical applications of the Power Grid Model.
-An update on the latest advancements in Power Grid -Model technology during the first and second quarters of 2024.
-An interactive brainstorming session to discuss and propose new feature requests.
-An opportunity to connect with fellow Power Grid Model enthusiasts and users.
How to Interpret Trends in the Kalyan Rajdhani Mix Chart.pdfChart Kalyan
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A Mix Chart displays historical data of numbers in a graphical or tabular form. The Kalyan Rajdhani Mix Chart specifically shows the results of a sequence of numbers over different periods.
Skybuffer AI: Advanced Conversational and Generative AI Solution on SAP Busin...Tatiana Kojar
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Skybuffer AI, built on the robust SAP Business Technology Platform (SAP BTP), is the latest and most advanced version of our AI development, reaffirming our commitment to delivering top-tier AI solutions. Skybuffer AI harnesses all the innovative capabilities of the SAP BTP in the AI domain, from Conversational AI to cutting-edge Generative AI and Retrieval-Augmented Generation (RAG). It also helps SAP customers safeguard their investments into SAP Conversational AI and ensure a seamless, one-click transition to SAP Business AI.
With Skybuffer AI, various AI models can be integrated into a single communication channel such as Microsoft Teams. This integration empowers business users with insights drawn from SAP backend systems, enterprise documents, and the expansive knowledge of Generative AI. And the best part of it is that it is all managed through our intuitive no-code Action Server interface, requiring no extensive coding knowledge and making the advanced AI accessible to more users.
A Comprehensive Guide to DeFi Development Services in 2024Intelisync
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DeFi represents a paradigm shift in the financial industry. Instead of relying on traditional, centralized institutions like banks, DeFi leverages blockchain technology to create a decentralized network of financial services. This means that financial transactions can occur directly between parties, without intermediaries, using smart contracts on platforms like Ethereum.
In 2024, we are witnessing an explosion of new DeFi projects and protocols, each pushing the boundaries of what’s possible in finance.
In summary, DeFi in 2024 is not just a trend; it’s a revolution that democratizes finance, enhances security and transparency, and fosters continuous innovation. As we proceed through this presentation, we'll explore the various components and services of DeFi in detail, shedding light on how they are transforming the financial landscape.
At Intelisync, we specialize in providing comprehensive DeFi development services tailored to meet the unique needs of our clients. From smart contract development to dApp creation and security audits, we ensure that your DeFi project is built with innovation, security, and scalability in mind. Trust Intelisync to guide you through the intricate landscape of decentralized finance and unlock the full potential of blockchain technology.
Ready to take your DeFi project to the next level? Partner with Intelisync for expert DeFi development services today!
Digital Marketing Trends in 2024 | Guide for Staying AheadWask
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https://www.wask.co/ebooks/digital-marketing-trends-in-2024
Feeling lost in the digital marketing whirlwind of 2024? Technology is changing, consumer habits are evolving, and staying ahead of the curve feels like a never-ending pursuit. This e-book is your compass. Dive into actionable insights to handle the complexities of modern marketing. From hyper-personalization to the power of user-generated content, learn how to build long-term relationships with your audience and unlock the secrets to success in the ever-shifting digital landscape.
GraphRAG for Life Science to increase LLM accuracyTomaz Bratanic
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GraphRAG for life science domain, where you retriever information from biomedical knowledge graphs using LLMs to increase the accuracy and performance of generated answers
Building Production Ready Search Pipelines with Spark and MilvusZilliz
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Spark is the widely used ETL tool for processing, indexing and ingesting data to serving stack for search. Milvus is the production-ready open-source vector database. In this talk we will show how to use Spark to process unstructured data to extract vector representations, and push the vectors to Milvus vector database for search serving.
HCL Notes und Domino Lizenzkostenreduzierung in der Welt von DLAUpanagenda
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Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-und-domino-lizenzkostenreduzierung-in-der-welt-von-dlau/
DLAU und die Lizenzen nach dem CCB- und CCX-Modell sind für viele in der HCL-Community seit letztem Jahr ein heißes Thema. Als Notes- oder Domino-Kunde haben Sie vielleicht mit unerwartet hohen Benutzerzahlen und Lizenzgebühren zu kämpfen. Sie fragen sich vielleicht, wie diese neue Art der Lizenzierung funktioniert und welchen Nutzen sie Ihnen bringt. Vor allem wollen Sie sicherlich Ihr Budget einhalten und Kosten sparen, wo immer möglich. Das verstehen wir und wir möchten Ihnen dabei helfen!
Wir erklären Ihnen, wie Sie häufige Konfigurationsprobleme lösen können, die dazu führen können, dass mehr Benutzer gezählt werden als nötig, und wie Sie überflüssige oder ungenutzte Konten identifizieren und entfernen können, um Geld zu sparen. Es gibt auch einige Ansätze, die zu unnötigen Ausgaben führen können, z. B. wenn ein Personendokument anstelle eines Mail-Ins für geteilte Mailboxen verwendet wird. Wir zeigen Ihnen solche Fälle und deren Lösungen. Und natürlich erklären wir Ihnen das neue Lizenzmodell.
Nehmen Sie an diesem Webinar teil, bei dem HCL-Ambassador Marc Thomas und Gastredner Franz Walder Ihnen diese neue Welt näherbringen. Es vermittelt Ihnen die Tools und das Know-how, um den Überblick zu bewahren. Sie werden in der Lage sein, Ihre Kosten durch eine optimierte Domino-Konfiguration zu reduzieren und auch in Zukunft gering zu halten.
Diese Themen werden behandelt
- Reduzierung der Lizenzkosten durch Auffinden und Beheben von Fehlkonfigurationen und ĂĽberflĂĽssigen Konten
- Wie funktionieren CCB- und CCX-Lizenzen wirklich?
- Verstehen des DLAU-Tools und wie man es am besten nutzt
- Tipps für häufige Problembereiche, wie z. B. Team-Postfächer, Funktions-/Testbenutzer usw.
- Praxisbeispiele und Best Practices zum sofortigen Umsetzen
Unlock the Future of Search with MongoDB Atlas_ Vector Search Unleashed.pdfMalak Abu Hammad
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Discover how MongoDB Atlas and vector search technology can revolutionize your application's search capabilities. This comprehensive presentation covers:
* What is Vector Search?
* Importance and benefits of vector search
* Practical use cases across various industries
* Step-by-step implementation guide
* Live demos with code snippets
* Enhancing LLM capabilities with vector search
* Best practices and optimization strategies
Perfect for developers, AI enthusiasts, and tech leaders. Learn how to leverage MongoDB Atlas to deliver highly relevant, context-aware search results, transforming your data retrieval process. Stay ahead in tech innovation and maximize the potential of your applications.
#MongoDB #VectorSearch #AI #SemanticSearch #TechInnovation #DataScience #LLM #MachineLearning #SearchTechnology
Programming Foundation Models with DSPy - Meetup SlidesZilliz
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Prompting language models is hard, while programming language models is easy. In this talk, I will discuss the state-of-the-art framework DSPy for programming foundation models with its powerful optimizers and runtime constraint system.
In the rapidly evolving landscape of technologies, XML continues to play a vital role in structuring, storing, and transporting data across diverse systems. The recent advancements in artificial intelligence (AI) present new methodologies for enhancing XML development workflows, introducing efficiency, automation, and intelligent capabilities. This presentation will outline the scope and perspective of utilizing AI in XML development. The potential benefits and the possible pitfalls will be highlighted, providing a balanced view of the subject.
We will explore the capabilities of AI in understanding XML markup languages and autonomously creating structured XML content. Additionally, we will examine the capacity of AI to enrich plain text with appropriate XML markup. Practical examples and methodological guidelines will be provided to elucidate how AI can be effectively prompted to interpret and generate accurate XML markup.
Further emphasis will be placed on the role of AI in developing XSLT, or schemas such as XSD and Schematron. We will address the techniques and strategies adopted to create prompts for generating code, explaining code, or refactoring the code, and the results achieved.
The discussion will extend to how AI can be used to transform XML content. In particular, the focus will be on the use of AI XPath extension functions in XSLT, Schematron, Schematron Quick Fixes, or for XML content refactoring.
The presentation aims to deliver a comprehensive overview of AI usage in XML development, providing attendees with the necessary knowledge to make informed decisions. Whether you’re at the early stages of adopting AI or considering integrating it in advanced XML development, this presentation will cover all levels of expertise.
By highlighting the potential advantages and challenges of integrating AI with XML development tools and languages, the presentation seeks to inspire thoughtful conversation around the future of XML development. We’ll not only delve into the technical aspects of AI-powered XML development but also discuss practical implications and possible future directions.
Main news related to the CCS TSI 2023 (2023/1695)Jakub Marek
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An English 🇬🇧 translation of a presentation to the speech I gave about the main changes brought by CCS TSI 2023 at the biggest Czech conference on Communications and signalling systems on Railways, which was held in Clarion Hotel Olomouc from 7th to 9th November 2023 (konferenceszt.cz). Attended by around 500 participants and 200 on-line followers.
The original Czech 🇨🇿 version of the presentation can be found here: https://www.slideshare.net/slideshow/hlavni-novinky-souvisejici-s-ccs-tsi-2023-2023-1695/269688092 .
The videorecording (in Czech) from the presentation is available here: https://youtu.be/WzjJWm4IyPk?si=SImb06tuXGb30BEH .
Ocean lotus Threat actors project by John Sitima 2024 (1).pptxSitimaJohn
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Ocean Lotus cyber threat actors represent a sophisticated, persistent, and politically motivated group that poses a significant risk to organizations and individuals in the Southeast Asian region. Their continuous evolution and adaptability underscore the need for robust cybersecurity measures and international cooperation to identify and mitigate the threats posed by such advanced persistent threat groups.
leewayhertz.com-AI in predictive maintenance Use cases technologies benefits ...alexjohnson7307
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Predictive maintenance is a proactive approach that anticipates equipment failures before they happen. At the forefront of this innovative strategy is Artificial Intelligence (AI), which brings unprecedented precision and efficiency. AI in predictive maintenance is transforming industries by reducing downtime, minimizing costs, and enhancing productivity.
10. The Monero Difference
SENDER RECEIVER
RING
SIGNATURES
STEALTH
ADDRESSES
AMOUNT TRANSACTION
BROADCAST
ɱ
KOVRI
(I2P ROUTER)
RING CONFIDENTIAL
TRANSACTIONS (RINGCT)
11. Ring Signatures & RingCT
8 (Tx ID hng6iwfumwf8)
9 (Tx ID cb8vqfi8dfj65f)
1 (Tx ID e4hn4ifqyd5ed)
3 (Tx ID wb4f5hdfdicnd)
4 (Tx ID nh5nogsefwjw)
6 (Tx ID ybwnng8nengf)
2 (Tx ID eshgni5lsvnf74)
5 (Tx ID fgwinw3fwtk54)
7 (Tx ID e4bgn8flwwrj8)
10 (Tx ID fnidmfnu3dm8)
11 (Tx ID twv8mf8dnfas)
13 (Tx ID 7nr8mrjffijdtm)
12 (Tx ID h5o8mfdngkd)
14 (Tx ID f8n8madkrjmd)
15 (Tx ID wn3f4diiijffwn)
16 (Tx ID 5 f8wnfdmmii)
17 (Tx ID h8fn5mdfi4w)
18 (Tx ID n48gfwmfdki)
20 (Tx ID t4vn8lf8djer4)
19 (Tx ID fnidmnfdsam)
21 (Tx ID 4f5f8njdoam4)
BLOCKCHAIN
8 (Tx ID hng6iwfumwf8)
5 (Tx ID fgwinw3fwtk54)
11 (Tx ID twv8mf8dnfas)
15 (Tx ID wn3f4diiijffwn)
18 (Tx ID n48gfwmfdki)
21 (Tx ID 4f5f8njdoam4)
12. Ring Signatures & RingCT
Ringsize=6
INPUTSMinimumSeptember2017*
MinimumToday
5 (Tx ID fgwinw3fwtk54)
8 (Tx ID hng6iwfumwf8)
11 (Tx ID twv8mf8dnfas)
15 (Tx ID wn3f4diiijffwn)
18 (Tx ID n48gfwmfdki)
21 (Tx ID 4f5f8njdoam4) key image
13. 5 (Tx ID fgwinw3fwtk54)5 (Tx ID fgwinw3fwtk54)
8 (Tx ID hng6iwfumwf8)
11 (Tx ID twv8mf8dnfas)
15 (Tx ID wn3f4diiijffwn)
18 (Tx ID n48gfwmfdki)
21 (Tx ID 4f5f8njdoam4)
Ring Signatures & RingCT
Ringsize=6
INPUTSMinimumSeptember2017*
MinimumToday
8 (Tx ID hng6iwfumwf8)
11 (Tx ID twv8mf8dnfas)
15 (Tx ID wn3f4diiijffwn)
18 (Tx ID n48gfwmfdki)
21 (Tx ID 4f5f8njdoam4) key image
RingCT ring signature,
signs difference
between commitments
? XMR
Pedersen commitment
rCT = x*G + a*H(G)
Commitment
public key
Random Number Actual Amount
18. Stealth Addresses
OUTPUTS
? XMR
Back to Sender
To Receiver
INPUTS
100 XMR
OR
hfk5yndjdmnfirwm5dnu
7yf8dji8fbwb4f5hdfdicnd
ey5f8ne58nh5nogsefwjw
58fmd8jhybwnng8nengf
5hfnq835hng6iwfumwf8
3348dqnqcb8vqfi8dfj65f
Commitment public key
19. Summary
5 (Tx ID fgwinw3fwtk54)
8 (Tx ID hng6iwfumwf8)
11 (Tx ID twv8mf8dnfas)
15 (Tx ID wn3f4diiijffwn)
18 (Tx ID n48gfwmfdki)
21 (Tx ID 4f5f8njdoam4)
? XMR
hfk5yndjdmnfirwm5dnu
7yf8dji8fbwb4f5hdfdicnd
ey5f8ne58nh5nogsefwjw
58fmd8jhybwnng8nengf
5hfnq835hng6iwfumwf8
3348dqnqcb8vqfi8dfj65f
Commitment public key
24. Regulatory Compliance and Transparency
A view key is used to
reveal all transactions for
a Monero account, or just
the key for a single
transaction
Transparency
View keys can be given to
selected parties, or can be
made public
Selected Parties
By publishing their view
key, charities can invite
easy public oversight
Charities
Children can be given
their own accounts, and
parents can monitor their
spending
Parents
(with the View Key)
Adapted from Riccardo Spagni’s Presentation
Let’s start by talking about centralized and decentralized systems. You are likely already familiar with both of these. As the names imply, a centralized system sends most traffic to a single point, while a decentralized system relies on several entities and several connections. For a centralized connection, imagine connecting to a website. You type the URL into the bar, and you create a direct connection between you and the website. If you share a file with someone over Google Drive, you upload a file to Google, and then the other party downloads from Google. With a decentralized system, all the participants connect to each other. There is no single entity that controls the swarm. Torrents are typically decentralized, and you will connect to several other peers to download and upload a file or folder. Centralized systems are typically more efficient since fewer connections are needed, and decentralized systems are typically more robust since it is harder to attack all peers instead of one centralized one.
There are many decentralized systems. Two you likely have heard of are BitTorrent and Tor. The first shares files on a decentralized network, and the second provides anonymous browsing through a series of nodes that can be run by anyone. Other projects you may not have heard of include Freenet, I2P, and Tox. Freenet attempts to provide internet services, I2P has its own P2P network for a variety of purposes, and Tox is best explained as a decentralized Skype. Bitcoin is also decentralized. The network is run on thousands of nodes worldwide, which can be run by anyone. No one needs to trust these nodes. Miners keep the network secure, and hundreds of thousands of machines worldwide compete against each other to create its own decentralized system. While there are always improvements to make these systems even more decentralized, it is important to realize that many services, especially those that aim to provide privacy, use decentralized networks to mitigate the trust needed to use a system. Decentralized services, therefore, are typically used to achieve 1) privacy, and/or 2) network robustness. Bitcoin is a great example of the second case, but not the first. We will discuss why later in this presentation.
In simple terms, Bitcoin is a decentralized network, where a history of the transactions is stored on thousands of computers around the world. This history is called the blockchain. The blockchain is a chain of blocks. Each block contains the most recent transaction history. There is a new block every 10 minutes. People will ask miners to include their transactions in the next block, often with a fee. The network automatically adjusts so that a new block can be added by one miner at random approximately every 10 minutes. Once a transaction is included in a block, it has a confirmation. People who are very cautious wait for several confirmations, since it is significantly harder to reverse an old transaction than a new one.
Bitcoin is not private! In fact, it is perhaps the most transparent money system ever made. Everyone in the world can see a history of the following:
The amount of money in a wallet
Where the Bitcoin came from
Where the Bitcoin went
This visualization shows the transfer of Bitcoin from large accounts to others. It is a visual representation of transfers of Bitcoin.
When people started realizing that Bitcoin is not private, they tried adding things on top of Bitcoin so some people could have privacy. This is traditionally done with a Bitcoin mixing or CoinJoin approach. Several people take their Bitcoin and send it to a centralized server. This centralized server then gives a random Bitcoin from among those received back to the users. Ideally, this could provide some untraceability, since the origin of the received funds is ambiguous. However, there are several fundamental issues with this type of approach.
The vast majority of people who use an optional system that costs extra which you need to go out of your way to use are people who have tainted coins. Tainted coins are coins that are known to previously be used for illicit purposes. An insignificant number of people pay money to mix clean coins. Thus, mixers do not work very well at providing plausible deniability. Instead, they make you stand out, since it makes it look like you are doing something wrong. Mixing itself is a shady act.
Second, you add a level of trust to the system. While Bitcoin is trustless, you need to trust the mixer you use with CoinJoin. They may choose to keep a history of the transaction information, and the people who use the service will never know. People must trust that the mixer does not act maliciously, which is a systemic risk with mixing services. In an ideal private system, you should not have to trust anyone else with your privacy.
Finally, from a convenience perspective, it takes a long time to mix coins, since you need to wait for other participants to mix with. If you plan to mix a large number of coins several times, it can take days or weeks. Few users will go through this effort.
Monero is different from a mixing service. It uses three technologies and a work-in-progress fourth technology to provide trustless privacy for all transactions. These technologies work together to protect different parts of a transaction. The sender is hidden with ring signatures. The amount is hidden with ring confidential transactions, or RingCT. The transaction broadcast is not currently hidden without extra steps, but Monero is working on Kovri, an I2P router, to hide this with no additional effort. The receiver is hidden with stealth addresses. All of these technologies will be addressed in this presentation.
Start by imagining the entire money supply of Euros or Dollars, all in one place. This supply is divided into different notes or bills of a certain value (10, 20, 50. etc). Monero is basically the same. The whole Monero money supply is contained in different outputs, each with a certain amount of Monero. One could be 0.01 XMR, and another could be 1000 XMR. Now imagine this red highlighted one is an output that you control. You have the ability to spend it, and it’s as if you had physical money in your wallet. When you make a Monero transaction, you want to hide what the origin of the funds are, since Monero tries to prevent the blacklisting of certain coins. Your wallet software will select other inputs from those available. These will be controlled by other people. You will appear to spend these amounts, along with your own, even without communicating with the real owner. Thus, by making it seem as if your red input is spent along with the other blue ones highlighted here, no one but you (the sender) knows what the origin of the money is.
The ring signature is just the process of taking your red (real) input, the blue ones (decoys), and making it seem as if they are all spent simultaneously. An outside observer does not know which is the real one, since they are all possible. In this example, the ringsize is 6, meaning that 6 total inputs (including your own) are used. As of August 2017, the minimum allowed by the network is 3. In September 2017, the minimum is expected to be increased to 5 or greater, since more decoys allows for better privacy. The key image is generated for the real input used. Nodes and miners can use this to verify that a real input is actually being spent, but they still do not know which input is real. The key image prevents attackers from spending money more than once or from spending money that does not exist.
For each of these inputs, a fraction is used according to a Pedersen commitment. It is not important to remember any important math on an introductory level, but know that the sender in a transaction spends a proportion of the input that only the sender knows. The commitment itself consists of two parts: 1) the actual amount a, which is hidden by adding 2) a random number x. Since no one knows what the random number is except the sender, an outside observer does not know how much is actually being spent. This commitment will be evaluated among the inputs and outputs, to make sure the same value is generated on both sides of the transaction. A range proof prevents the sender from using a different random number for the input and output set. Finally, the transaction is fully signed as a RingCT ring signature, resulting in an unknown amount of Monero sent to the receiver or receivers. As an output, the commitment public key is published to allow the network to audit the math done behind the Pedersen commitment.
Now that we have looked into how the inputs for a single transaction are hidden among others, it can be helpful to look at how inputs are used over time. The same inputs as before are on the left. The history for the red one is shown on a hypothetical blockchain on the right. The older blocks are on the left, and the newer blocks are on the right. The blocks highlighted red signify to the times that this input was included. There are three ways this could happen:
It is new money from a Coinbase transaction. This is known to everyone on the network. They do not know what address controls it.
The input was actually spent by the real controller
The input was borrowed an used as a decoy in another transaction
Since there is no way to differentiate between 2 and 3, there is no way of knowing whether an input is actually spent, even if it appears in a specific block.
The hardest part to get right with Monero is the input selection algorithm. Monero needs to choose the decoy inputs convincingly to hide the real input. When Monero first launched, other inputs were selected at pure random. This may sound good, but this is actually really bad, since people are much more likely to spend new money than money that has been sitting around in a wallet for a while. Thus, Monero now uses an improved triangular distribution algorithm to heavily prefer newer inputs over older ones. Monero will continually need to improve the selection algorithm to accommodate for changing spending preferences.
When you tell the network that you would like for them to include your transaction in the next block, you can leak some very important information about yourself, even if the transaction itself is obfuscated. Some nodes on the network may be logging the IP address that they receive these requests from. Fortunately, it is very difficult for an attacker to know that this is the real origin of the transaction, but they can still make an educated guess. Then, they could knock on your door and demand your private key. Not good. Or perhaps an ISP could say they purposefully block connection to the Monero network. Not good either. Kovri will allow people to hide their IP address and, optionally, hide from one’s ISP that Monero is even being used at all. This is done by tunneling connections though the I2P network. I2P is similar to Tor with a few important differences. Every node is a participant on the network, which allows Monero to contribute to I2P rather than just mostly leeching off Tor. In any case, Kovri will allow users to protect their connection information locally and from outside attackers.
Instead of an attacker getting one’s real IP address, they would instead get a meaningless, disposable I2P address. We cannot prevent nodes from logging or even know which nodes log, but we can give nodes garbage information. That’s what Kovri does.
Finally, Monero hides where the money is going to with stealth addresses. Instead of sending money directly to an address, Monero is essentially locked in a container. Every account must search each of these containers to know which is for them, but only one account can open the container. Furthermore, no one else knows who the container is for. This is how stealth addresses work on a very basic level. Outside observers don’t even know these outputs from a single transaction go to one person. They could go to several people. In this example, the red ones go to the receiver, and the blue ones come back to the sender as change. This change can be used to break up large inputs (say they have 100 XMR but only want to send 10 XMR to someone. Then, they can send 90 XMR back as change).
In summary, for any given transaction, Monero is sent from an ambiguous source, from which an unknown amount is committed and thus an unknown amount is sent, to an unknown receiver or set of receivers. As you can see, all information stored on the blockchain is obfuscated by mandate.
One thing the Monero community is particularly vocal about is the idea of mandatory privacy. We feel that all transactions must be private or else it doesn’t really matter. Before early 2016, only 1/3 of Monero transactions hid the origin of funds, which was not good for several reasons. The individual transaction is not private, and those who need privacy get less if fewer people use the privacy features. Now, it is impossible to send a transaction without hiding the origin of funds in the ring signature. Other coins claim to offer excellent privacy, but most fail in execution to provide privacy to any meaningful number of users.
This is what the official GUI currently looks like. It is available on a variety of platforms.
This is what the upcoming MyMonero open-source lightweight wallet will look like. It will allow users of Monero to connect to the network in a more sustainable way if they do not wish to run a full node.
Monero can be optionally transparent if the user wants it to be, while only revealing this information to the intended recipient, not the whole world. The Monero project uses this method, publishing the view key with the address on the official website. Now, people can see the amount that comes in from donations.