Tezos Unleashed Session on 24th March 2024

1. Cryptography
Cryptography
the concept of cryptography in
blockchain

2. What is cryptography?
1. 3. How cryptography is used to secure
information in blockchain
2. Two main types of cryptography 4. Advantages of cryptography in
blockchain
Agenda
Topics Covered
5. Cryptographic Hash Function

3. What is
cryptography?

4. Cryptography is a technique or
protocol that secures information
from any third party during
communication. The word is
composed of two Greek terms, the
term Kryptos meaning “hidden,”
and Graphein, meaning “to write”.
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5. Two main types
of cryptography

6. Symmetric-key Cryptography
Asymmetric-key Cryptography
Basic cryptography technologies
can include two types of
encryptions:
Types of Cryptography

8. Symmetric key encryption is a method that utilizes a
single shared secret key for both encrypting and
decrypting data.
This makes it efficient for tasks like securing website
connections or encrypting data. However, the key
challenge lies in securely exchanging this secret key
between the sender and receiver before communication
can begin.
Common examples of symmetric key algorithms include
AES (Advanced Encryption Standard) and DES (Data
Encryption Standard).
SYMMETRIC KEY ENCRYPTION

9. It is also described as secret key cryptography.
Both parties have the same key to keep the secret.
It is suitable for bulk encryption.
It requires less processing power and faster
transfer.
Features of Symmetric-key Cryptography:

11. Asymmetric key encryption is a different approach that
utilizes two distinct keys: a public key and a private
key.
The public key can be freely shared with anyone, while
the private key must be kept confidential.
This method is particularly useful for secure
communication scenarios like sending emails or
browsing the web.
For instance, when you visit a website secured with
HTTPS, asymmetric key encryption safeguards the
communication between your device and the web server.
ASYMMETRIC KEY ENCRYPTION

12. It is described as public key cryptography.
It is often used for symmetric cryptography secret key
sharing.
It requires a long processing time to execute.
It plays a significant role in the authenticity of the
web server.
FEATURES OF ASYMMETRIC-KEY CRYPTOGRAPHY:
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13. How cryptography
is used to secure
information in
blockchain ?

14. Cryptography is used to encrypt transactions on the blockchain
network. This encryption protects the information and
communications from unauthorized access. Public key
encryption is specifically used to accomplish this task.
1.
Cryptography uses hashing algorithms to create a unique
identifier for each block of data in the blockchain. This
hashing function helps to ensure the immutability of the
blockchain. If any data in a block were changed, the hash
would also change, and this would be easily detectable.
2.
Digital signatures are used to verify the authenticity of
transactions. Digital signatures are created with cryptography.
3.
SECURITY IN BLOCKCHAIN:
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15. Advantages of
cryptography in
blockchain

16. Encryption: Ensures secure transactions
1.
Immutability: Allows tamper-proof data
2.
Security: Provides transaction security through encryption
3.
Scalability: Enables secure record keeping
4.
Non-repudiation: Offers undeniable transactions
5.
ADVANTAGES:
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17. Cryptographic
Hash Function

18. Cryptographic hashing is a major function used in blockchain
technology.
It helps to ensure the immutability of the blockchain. When a
transaction is verified, a hashing algorithm adds a hash to the
block, and a new unique hash is created. This creates a chain of
blocks where any change to a block would be noticeable.
Hashing functions are used to link blocks together and maintain the
integrity of the data in the blockchain.
Some commonly used hash functions are MD5 and SHA-256.
CRYPTOGRAPHIC HASH FUNCTION:

20. For a particular message, the hash function does not change.
Any minor change in the data will result in a major change in the
hash value.
The input value is not predicted from the output hash function.
They are fast and efficient because they rely heavily on bitwise
operations.
PROPERTIES OF A CRYPTOGRAPHIC HASH
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21. Thank you!
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22. Resource Page
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Tezos

23. SNS Tezos Blockchain Club
Tezos
Unleashed
Introduction to Blockchain
24.03.2024
SNS College of Engineering
BY SUNIL N

24. 1 What is Blockchain?
2 What is a Block?
3 How Blockchain Works?
4 Terminologies
Agenda
SNS College of Engineering

25. What is
Blockchain? Blockchain is a decentralized digital
ledger that records transactions across a
network of computers.
It is a secure and transparent way to store
and transfer data, without the need for
intermediaries like banks or governments.
SNS College of Engineering

26. Blockchain
Digital Ledger Decentralized Network of Computers
SNS College of Engineering

27. What's in a Block?
A block is a collection of data.
Each block contains data, a unique hash
code, and a hash code referencing the
previous block.
A hash is like a fingerprint for the block's
content. If anything changes within the
block, the hash changes as well.
The hash of the previous block being
included in each new block creates a
chronological chain.
SNS College of Engineering
Data (e.g., transaction details)
Hash
Hash of previous block

28. SNS College of Engineering

30. So is Blockchain a Linked List?
Kind of similar.
Both use a chained structure where blocks
(data) are linked together.
Differences:
By design, data in a blockchain is very difficult to
alter. Any change would require modifying all
subsequent blocks and gaining control over a
majority of the network (almost impossible).
Distributed across a network of computers, with
no single point of control.
More complex system involving cryptography,
hashing, and network consensus mechanisms.
SNS College of Engineering

31. How Blockchain Works?
SNS College of Engineering

32. TERMINOLOGIES

33. A blockchain is decentralized, which means that it is
not controlled by any single person or entity.
Instead, it is maintained by a network of computers
around the world.
Anyone can participate in the blockchain network by
running a mining computer.
Because everyone has a copy of the blockchain, it is
very difficult to tamper with the data on the
blockchain. If someone tries to change a block, all of
the following blocks would also need to be changed,
which would require a lot of computing power.
Decentralization

34. Mining
Mining is the process of adding a new block to the
blockchain. Miners compete to solve a
mathematical puzzle in order to validate a block of
transactions.
The puzzle is to find a random number that, when
added to the data in the block, results in a hash that
starts with a certain number of zeros. The more
zeros required, the more difficult it is to solve the
puzzle.
The first miner to solve the puzzle gets to add the
block to the blockchain and is rewarded with
cryptocurrency.

35. Hashing function
A hashing function is a mathematical function that
turns data of any size into a fixed-size alphanumeric
code, called a hash.
Bitcoin uses SHA-256 as hashing function.
Even a small change in the input data results in a
completely different hash.
It takes time to compute a hash. The more complex
the data, the longer it takes to compute the hash.

36. Smart Contracts
A self-executing program stored on a blockchain
that automatically carries out the terms of an
agreement when certain conditions are met.
The code defining the agreement is written in a
specific programming language for the chosen
blockchain platform (e.g., Solidity for Ethereum,
Ligo for Tezos).
A popular library for writing smart contracts on
Tezos. It allows developers to write smart contracts
in Python

37. :
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