This presentation shows the basics of the RSA cipher in an attractive way. You can easily understand how the cipher works, while learning the basic mathematical operations you need.
An animated version can be found at:
http://www.cryptool.org/images/ct1/presentations/RSA/RSA-Flash-en/player.html
Cryptography and Symmetric Key Algorithms
Cryptography is the study of secure communications techniques that allow only the sender and intended recipient of a message to view its contents.
OR
The art of creating and implementing secret codes and ciphers is known as cryptography.
This presentation shows the basics of the RSA cipher in an attractive way. You can easily understand how the cipher works, while learning the basic mathematical operations you need.
An animated version can be found at:
http://www.cryptool.org/images/ct1/presentations/RSA/RSA-Flash-en/player.html
Cryptography and Symmetric Key Algorithms
Cryptography is the study of secure communications techniques that allow only the sender and intended recipient of a message to view its contents.
OR
The art of creating and implementing secret codes and ciphers is known as cryptography.
Basic Talk. 90 minute talk to an audience of Freshmen and Sophomores of IIT Bombay on 23/02/10 as a part of Science Week. Organised by Web and Coding Club. Place: GG 101 (Elec Department)
Information and network security 15 other poly alphabatic ciphersVaibhav Khanna
A polyalphabetic cipher is any cipher based on substitution, using multiple substitution alphabets. The Vigenère cipher is probably the best-known example
Data Security on Computer Network and Telecommunication System Using Caesar C...Yekini Nureni
In this era of global communication where online communication through the use of computer network and telecommunication system has dominated the means of communication between people. The goal of privacy is very paramount. The numbers of people being connected to the communication system through their mobile phone, computer or any other e-communication tools are increasing day-by-day. Hence there is need to secure the communication networks from adversaries (third parties) between the sender and receivers. There are many aspects to security approach in data communication environment. One essential aspect for secure communications is that of cryptography, which the focus of this research is. We have developed stand-alone application software that implements cryptography using Caesar algorithms. This program can be implemented with chatting software or E-mail software to encrypt data. The algorithm was coded with Java programming language.
Quantum cryptography can, in principle, provide unconditional security guaranteed by the law of physics only. Here, we survey the theory and practice of the subject and highlight some recent developments.
Basic Talk. 90 minute talk to an audience of Freshmen and Sophomores of IIT Bombay on 23/02/10 as a part of Science Week. Organised by Web and Coding Club. Place: GG 101 (Elec Department)
Information and network security 15 other poly alphabatic ciphersVaibhav Khanna
A polyalphabetic cipher is any cipher based on substitution, using multiple substitution alphabets. The Vigenère cipher is probably the best-known example
Data Security on Computer Network and Telecommunication System Using Caesar C...Yekini Nureni
In this era of global communication where online communication through the use of computer network and telecommunication system has dominated the means of communication between people. The goal of privacy is very paramount. The numbers of people being connected to the communication system through their mobile phone, computer or any other e-communication tools are increasing day-by-day. Hence there is need to secure the communication networks from adversaries (third parties) between the sender and receivers. There are many aspects to security approach in data communication environment. One essential aspect for secure communications is that of cryptography, which the focus of this research is. We have developed stand-alone application software that implements cryptography using Caesar algorithms. This program can be implemented with chatting software or E-mail software to encrypt data. The algorithm was coded with Java programming language.
Quantum cryptography can, in principle, provide unconditional security guaranteed by the law of physics only. Here, we survey the theory and practice of the subject and highlight some recent developments.
Creating interactive digital books for the transition from secondary to under...Christian Bokhove
In the United Kingdom, many students struggle in their transition from secondary school mathematics to undergraduate mathematics. It is not always possible to remediate deficiencies in mathematical knowledge within a school setting. At the same time, we know that Intelligent Tutoring Systems can aid students in acquiring, practicing, and assessing mathematical content. In this paper, we will present interactive workbooks created at our institution, that cover units of study from the secondary A-level mathematics curriculum, comprising a series of technical expositions and a modular collection of quizzes. Each quiz addresses content equivalent of at most two classroom lessons and features automated feedback bespoke to the students’ (algebraic or numeric) input. The ‘digital books’ make use of a Computer Algebra System to provide automated feedback. The development of the books is a collaborative process in a ‘Community of Interest’ with local secondary teachers, developers recruited from local departments, and the Southampton Education School. An iterative design-based research approach was adopted for the development, with multiple opportunities for feedback and improvement. After initial prototyping, a teacher focus group will attend a follow-up session where they are invited to review the materials and to make suggestions or requests before implementing them with their students later in the year. We present preliminary reflections on the results of our reflective design-based process, and discuss how this process contributes to both better digital books and research insights.
Help-seeking in an online maths environment: A sequence analysis of log filesChristian Bokhove
In online mathematics environments feedback is often provided to help students make progress. However, the extent to which students make use of such feedback, so-called ‘help-seeking’, depends on numerous instructional variables, including the design of the online platform and individual student characteristics. Furthermore, student behaviour in such platforms are not independent events: the order in which tasks are completed matters, and we therefore have to study sequences of such events. This study used student data from UK students in grades 3 to 5 with at least 100 lesson records in the academic year ’18-’19 (N=1,799), totalling 1,048,575 records between December 2010 and January 2019, from an online mathematics platform. Sequence analysis was applied to the data to uncover patterns of help-seeking. The results showed that help, task difficulty and precision interact, demonstrating the usefulness of learning analytical approaches like sequence analysis.
Learning loss and learning inequalities during the covid-19 pandemic: an anal...Christian Bokhove
The transition to distance schooling during the pandemic has exacerbated inequalities by socio-economic status (SES) due both to the gap in the volume of schoolwork completed and to the relative ability or inability of some parents to support their children’s learning. In this presentation I will report on a longitudinal analysis of Understanding Society data from the two school closures in April 2020 and January 2021, which colleagues Dr Nic Pensiero, Prof Tony Kelly and I conducted for the ESRC. The analysis included parents' occupations, computer availability and parents' work patterns. The provision of schoolwork improved in both primary and secondary schools in the second closure period compared to the first school closure period, with the increased provision explained by the more lessons, greater availability of computers and families being better prepared for the second school closure. While parental occupation alone was found to be a significant determinant of differences in the volume of schoolwork among students, its effect was amplified when combined with student access to computers, family circumstances and parental working patterns. Primary school children of single parents who worked from home were able to reduce the gap in schoolwork done compared to the most advantaged socio-economic group, but generally, inequalities between socio-economic groups in the uptake of schoolwork remained stable between the two school closure periods. I will discuss what these findings have taught us.
The challenge of proof in the transition from A-level mathematics to universityChristian Bokhove
Students’ difficulties with mathematical proof and transition from secondary to university mathematics are key topics within mathematics education research. In this talk, we report on research with the Southampton Mathematics department and A-level mathematics teachers. In the transition from A-level maths and further maths to undergraduate mathematics, the topic of proof always is a big challenge for students. In our study, we analysed answers to a ‘proof by induction’ task from first-year undergraduate mathematics students. Findings show that many students find the proof by induction process challenging. Results illustrate the difficulties students face when they are asked to engage with a proof by induction task within the Calculus context and provide insight into the transition from A-level maths to undergraduate maths. We highlight how a multidisciplinary team of mathematics specialists (mathematics education researchers, secondary maths teachers, mathematicians) created a resource to support A-level teachers, trialled in this academic year. The booklet ‘Thinking about Proof’ supports A-level teachers in teaching proof and facilitating a smoother transition to university mathematics.
(On)waarheden en (on)bekende zaken uit onderzoek over reken-wiskundeonderwijsChristian Bokhove
(On)waarheden en (on)bekende zaken uit onderzoek over reken-wiskundeonderwijs
Als je de geluiden in de media mag geloven, dan staat het reken-wiskundeonderwijs of elk moment op instorten of gaat het prima. Vaak worden deze claims kracht bijgezet door het citeren van onderzoek. Sommige criticasters zeggen dan ook wel dat je met onderzoek alles kunt bewijzen.
In deze lezing kijk ik naar verschillende bronnen die worden aangehaald bij discussies over het reken-wiskundeonderwijs. Onderwerpen die de revue passeren zijn:
• Wat internationale en nationale peilingen over de stand van ons reken-wiskundeonderwijs zeggen.
• Het complementaire karakter van vaardigheden en inzicht.
• Onderzoeksthema’s die veelvuldig langskomen in discussies, bijvoorbeeld met de inspectie en de recente NPO menukaart. Van enkele van deze thema’s, geef ik concrete voorbeelden hoe onderzoek soms ge- en mis-bruikt wordt.
Ik zal aangeven hoe onderzoek gezamenlijk vaak een pluriform en genuanceerd beeld van het reken-wiskundeonderwijs geeft, maar dat het belangrijk is om breed te lezen, de context te bevragen, en dieper te graven dan simplistische slogans.
Methodological innovation for mathematics education researchChristian Bokhove
In this talk I will highlight how innovative research methods can help us in answering research questions for mathematics education. Some examples will be:
The use of social network analysis for communication networks of trainee mathematics teachers, as well as interactions in the mathematics classroom.
The use of sequence analysis for analysing data from an online mathematics tool.
The usefulness of open approaches to improve research transparency.
I will draw these projects together to sketch some interesting directions for mathematics education research.
In England, an important role for the judgement of educational quality, is provided by the national school inspectorate Ofsted. Periodically they inspect schools and judge them. The result of the inspection is captured in inspection reports and associated documents. Ofsted has had several chief inspectors (HMCI) since 2000 and every HMCI tends to put his/her own mark on the inspectorate. This paper extends the analysis of the corpus in Author (2020) using the corpus of more than 17,000 Ofsted documents which were scraped from their website with text-mining techniques. Using the computational research method of structural topic modelling I re-analyse a set of documents that typically could not be analysed with manual methods. I juxtapose the findings with previous findings from sentiment analyses. The paper does not just cover the substantive topic at hand, but also provide insight in how the methods work, and how they provide insight in policy shifts during the ‘reign’ of different HMCIs. All in all, we can see how such text-mining techniques allow us to analyse existing documents at scale.
Learning loss and learning inequalities during the Covid-19 pandemic: an anal...Christian Bokhove
For the report see https://www.southampton.ac.uk/publicpolicy/covid19/learning-inequalities-covid-19.page
For a recording of the talk see: https://login.microsoftonline.com/common/oauth2/authorize?client_id=cf53fce8-def6-4aeb-8d30-b158e7b1cf83&response_mode=form_post&response_type=code+id_token&scope=openid+profile&state=OpenIdConnect.AuthenticationProperties%3dAQAAAAIAAAAJLnJlZGlyZWN0YWh0dHBzOi8vd2ViLm1pY3Jvc29mdHN0cmVhbS5jb20vdmlkZW8vZjQzMTlhOGItNjI3ZC00MjVmLTkxNzgtNjUxNmJiMjRjNjA2P3JlZmVycmVyPWh0dHBzOi8vdC5jby8Ibm9uY2VLZXmbAWI3NThsQVZjX0dBV1l3elM1M1E4aUNMeklxeEhGck0yWlpFdjFKOW9DZDBfdHZURHZUVmFkcXJmNEF1YXBFeW9vc2JaSlVfSEFZeGRvaTB4Znpha3hlLURfNmFTR3VMb2tnVm55QjRjTU40TzctbnU5WFlvYU5YaS00LThocjhubFh6LWxXejRZelFSOTZSZ2hXTzY3VjlOS2tF&nonce=637623831282885943.OTE1YmY1ZGMtMmNlZC00MTAyLWFkN2ItNDBjMDQ0N2YzNWIxYzQ2ODYxMTMtNjkyOC00MjMxLWI3M2QtOTg2MjY5NDU1NTMz&nonceKey=OpenIdConnect.nonce.7YqZnnSsGsmDUjch5zMsEl3cEhi9f8LQh3pftMQ0ZWU%3d&site_id=500453&redirect_uri=https%3a%2f%2fweb.microsoftstream.com%2f&post_logout_redirect_uri=https%3a%2f%2fproducts.office.com%2fmicrosoft-stream&msafed=0&prompt=none
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Safalta Digital marketing institute in Noida, provide complete applications that encompass a huge range of virtual advertising and marketing additives, which includes search engine optimization, virtual communication advertising, pay-per-click on marketing, content material advertising, internet analytics, and greater. These university courses are designed for students who possess a comprehensive understanding of virtual marketing strategies and attributes.Safalta Digital Marketing Institute in Noida is a first choice for young individuals or students who are looking to start their careers in the field of digital advertising. The institute gives specialized courses designed and certification.
for beginners, providing thorough training in areas such as SEO, digital communication marketing, and PPC training in Noida. After finishing the program, students receive the certifications recognised by top different universitie, setting a strong foundation for a successful career in digital marketing.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
TESDA TM1 REVIEWER FOR NATIONAL ASSESSMENT WRITTEN AND ORAL QUESTIONS WITH A...
Cryptography
1. CRYPTOGRAPHY
Dr Christian Bokhove
Professor in Mathematics Education
Disclaimer: I too am standing on the shoulders of giants and have made use of many
excellent resources on the web.
https://is.gd/y9crypto
2. What is it?
Cryptography – maths in service of security
Cryptanalysis – breaking cryptographic systems
3. Four functions
Confidentiality – “set of rules that limits access”
Integrity – “consistency and accuracy of
data throughout its life-cycle”
Authentication – “confirms a truth claimed
by some entity”
Non-repudiation – “ensure that the author of a piece
of information cannot deny it”
5. Origins of Cryptography
• Thought that the earliest form of cryptography was in the
Egyptian town of Menet Khufu
• The hieroglyphics on the tomb of nobleman
KHNUMHOTEP II contained unusual symbols, used to
obscure the meaning of the inscriptions.
1900 BC
Menet Khufu
Method: substitution
6. Origins of Cryptography
• The Spartans, in 5 BC,
developed a device called
a Scytale.
• A messenger would carry
a strip of parchment, which
was meaningless until it
was wrapped around a
Scytale of the same
dyameter.
• https://www.cryptool.org/en
/cto/scytale
Method: transposition
7. Caesar Cipher: c = m + 3
Caesar Shift Cipher
• Each letter was substituted by shifting n places
• Only 25 possible ciphers.
7
Julius Caesar
100 BC- 44 BC
8. Caesar Cipher
Many people will have tried this!
+m
A->C
B->D
C->E etc
a b c d e f g h I j k l m n o p q r s t u v w x y z
a b c d e f g h I j k l m n o p q r s t u v w x y z
Let m == 3, then the cleartext CAT
becomes the ciphertext FDW
15. Until modern times, cryptography referred almost exclusively to "encryption",
which is the process of converting ordinary information (called plaintext) into an
unintelligible form (called ciphertext).[13] Decryption is the reverse, in other words,
moving from the unintelligible ciphertext back to plaintext. A cipher (or cypher) is a
pair of algorithms that carry out the encryption and the reversing decryption. The
detailed operation of a cipher is controlled both by the algorithm and, in each
instance, by a "key". The key is a secret (ideally known only to the communicants),
usually a string of characters (ideally short so it can be remembered by the user),
which is needed to decrypt the ciphertext. In formal mathematical terms, a
"cryptosystem" is the ordered list of elements of finite possible plaintexts, finite
possible cyphertexts, finite possible keys, and the encryption and decryption
algorithms that correspond to each key. Keys are important both formally and in
actual practice, as ciphers without variable keys can be trivially broken with only the
knowledge of the cipher used and are therefore useless (or even counter-
productive) for most purposes. Historically, ciphers were often used directly for
encryption or decryption without additional procedures such as authentication or
integrity checks.
15
https://en.wikipedia.org/wiki/Cryptography
16. Vigenère
• The Vigenère cipher is a polyalphabetic cipher. The relationship
between a character in the plaintext to a character in the
cipher text is one-to-many.
• Blaise de Vigenère, a 16th century French mathematician.
• It was used in the American civil war and was once believed to
be unbreakable.
• A Vigenère cipher uses a different strategy to create the key
stream. The key stream is a repetition of an initial secret key
stream of length m, where we have 1 ≤ m ≤ 26.
• The Vigenère cipher is a method of encrypting alphabetic text
by using a series of different Caesar ciphers based on the
letters of a keyword.
• The Vigenère cipher uses multiple mixed alphabets, each is a
shift cipher.
17. Modular arithmetic
• Telling time is famously ‘modular arithmetic’.
• Can see it as arithmetic with remainders:
20 divided by 7 remainder is 6.
• The alphabet consists of 26 letters. Let’s number them 0,
1, 3, 4….., 25.
• What if I would do B+C?
That would be 1+2=3 and that’s D.
• What if I do R+T? That’s 17+19 = 36.
• But the alphabet doesn’t go that high, so start counting
from 0 again after 25, so that’s 10, or K.
• This is arithmetic ‘modulo 26’
• Notation: 17 + 19 mod 26 = 10.
18. Vigenere Cipher
We can encrypt the message “She is listening” using
the 6-character keyword “PASCAL“. The initial key stream
is (15,0,18,2,0,11). The key stream is the repetition of this
initial key stream (as many times as needed) .
Use encryption algorithm:
20. Vigenere Cipher
• This method was actually discovered earlier, in 1854 by
Charles Babbage.
• Vigenere-like substitution ciphers were regarded by many
as practically unbreakable for 300 years.
• In 1863, a Prussian major named Kasiski proposed a
method for breaking a Vigenere cipher that consisted of
finding the length of the keyword and then dividing the
message into that many simple substitution cryptograms.
22. Government Communications Headquarters
• During WWI, the British Army had a separate division from
the British Navy (“Room 40”).
• After WWI, it was proposed that a peacetime
codebreaking division be created.
• The Government Communications Headquarters was
created.
• Pre WWII, was a very small department.
• By 1940, was attacking codes of 26 countries and over
150 diplomatic cryptosystems.
• In USA many developments during WWII, including
Elizabeth Friedman, Grace Hopper and others.
23. World War II Cryptography
• Most Famous example of
Cryptography in World War
II was the German
Enigma.
• Made use of Rotors and
Plugboards
• One or more of the rotors
moved after each key
press, depending on the
settings.
• Created a changing
substitution cypher, or a
polyalphabetic substitution
cypher.
https://www.cryptool.org/en/cto/enigma-step-by-step
24. RSA Encryption
• Developed by Ron Rivest, Adi Shamir, and Leonard
Adleman.
• Type of Public Key Encryption.
• Later discovered that a similar method had been
developed by the GCHQ (The British SIGINT agency), in
1973, but was kept classified until 1997.
• “The security of RSA is based on the fact that it is easy to
calculate the product n of two large primes p and q.
However, it is very difficult to determine only from the
product n the two primes that yield the product. This
decomposition is also called the factorization of n.”
25. Prime numbers
• A prime number only has 1 or itself as ‘factor’.
• So, 7 is prime
• 13 is prime
• 21 is not prime because that can also be 3*7
• No even number is prime because 2 is always a factor.
• It’s not even always easy to know whether a(n odd)
number is prime or not.
26. Example
11677
39727
Easy to do: 11677 times 39727 is 463892179
Not so easy to do: what product of prime numbers
is 463892179 ?
28. Current day cryptography
• E.g. DES uses a 56-bit key, so 256 possible keys.
• 72,057,594,037,927,936 keys (72 thousand billion in the
UK, 72 quadrillion in the US)
• Even with all these keys, still susceptible to brute force
attacks.
• “It is known that the NSA encouraged, if not persuaded,
IBM to reduce the key size from 128 to 64 bits, and from
there to 56 bits; this is often taken as an indication that
the NSA possessed enough computer power to break
keys of this length even in the mid-1970s.” (Wikipedia)
• Many uses: Whatsapp, banking, https, 802.11, WPA,
GSM, Bluetooth, encrypting files on disk, content
protection on DVD/Blu-ray, user authentication.