Classical ciphers

Copiale cipher

The Copiale cipher is an encrypted manuscript consisting of 75,000 handwritten characters filling 105 pages in a bound volume. Undeciphered for more than 260 years, the document was cracked in 2011 with the help of modern computer techniques. An international team consisting of Kevin Knight of the University of Southern California Information Sciences Institute and USC Viterbi School of Engineering, along with Beáta Megyesi and Christiane Schaefer of Uppsala University in Sweden, found the cipher to be an encrypted German text. The manuscript is a homophonic cipher that uses a complex substitution code, including symbols and letters, for its text and spaces. Previously examined by scientists at the German Academy of Sciences at Berlin in the 1970s, the cipher was thought to date from between 1760 and 1780. Decipherment revealed that the document had been created in the 1730s by a secret society called the "high enlightened (Hocherleuchtete) oculist order" of Wolfenbüttel, or Oculists. The Oculists used sight as a metaphor for knowledge. A parallel manuscript is kept at the Staatsarchiv Wolfenbüttel. The Copiale cipher includes abstract symbols, as well as letters from Greek and most of the Roman alphabet. The only plain text in the book is "Copiales 3" at the end and "Philipp 1866" on the flyleaf. Philipp is thought to have been an owner of the manuscript. The plain-text letters of the message were found to be encoded by accented Roman letters, Greek letters and symbols, with unaccented Roman letters serving only to represent spaces. The researchers found that the initial 16 pages describe an Oculist initiation ceremony. The manuscript portrays, among other things, an initiation ritual in which the candidate is asked to read a blank piece of paper and, on confessing inability to do so, is given eyeglasses and asked to try again, and then again after washing the eyes with a cloth, followed by an "operation" in which a single eyebrow hair is plucked. (Wikipedia).

Copiale cipher
Video thumbnail

Symmetric Key Cryptography: The Keyword Cipher

This is the second in a series about cryptography; an extremely important aspect of computer science and cyber security. It covers a substitution cipher called the keyword cipher, also known as the Vigenère cipher. It explains how a keyword, or key phrase, can be used to effectively gene

From playlist Cryptography

Video thumbnail

Vigenere Cipher - Decryption (Known Key)

This video shows how to decrypt the ciphertext when the key is known. Decryption (unknown key): http://youtu.be/LaWp_Kq0cKs Encryption: http://youtu.be/izFivfLjD5E

From playlist Cryptography and Coding Theory

Video thumbnail

Vigenere Cipher - Encryption

This video is about the Vigenere Cipher: years used, key format, encryption. Note: sorry, I may have mispronounced names. Decryption (known key): http://youtu.be/oHcJ4QLiiP8 Decryption (unknown key): http://youtu.be/LaWp_Kq0cKs

From playlist Cryptography and Coding Theory

Video thumbnail

Bayesian Networks 9 - EM Algorithm | Stanford CS221: AI (Autumn 2021)

For more information about Stanford's Artificial Intelligence professional and graduate programs visit: https://stanford.io/ai Associate Professor Percy Liang Associate Professor of Computer Science and Statistics (courtesy) https://profiles.stanford.edu/percy-liang Assistant Professor

From playlist Stanford CS221: Artificial Intelligence: Principles and Techniques | Autumn 2021

Video thumbnail

Cryptanalysis of Vigenere cipher: not just how, but why it works

The Vigenere cipher, dating from the 1500's, was still used during the US civil war. We introduce the cipher and explain a standard method of cryptanalysis based on frequency analysis and the geometry of vectors. We focus on visual intuition to explain why it works. The only background

From playlist Classical Cryptography

Video thumbnail

Symmetric Key Cryptography: The Caesar Cipher

This is the first in a series about cryptography; an extremely important aspect of computer science and cyber security. It introduces symmetric key cryptography with a well known substitution cipher, namely the Caesar Cipher. It includes a few examples you can try for yourself using diff

From playlist Cryptography

Video thumbnail

Bayesian Networks 3 - Maximum Likelihood | Stanford CS221: AI (Autumn 2019)

For more information about Stanford’s Artificial Intelligence professional and graduate programs, visit: https://stanford.io/2Zlc5Iu Topics: Bayesian Networks Percy Liang, Associate Professor & Dorsa Sadigh, Assistant Professor - Stanford University http://onlinehub.stanford.edu/ Associa

From playlist Stanford CS221: Artificial Intelligence: Principles and Techniques | Autumn 2019

Video thumbnail

Vigenere Cipher - Decryption (Unknown Key)

This video shows the process (thoroughly) of how to find the key when you don't have it. English alphabet frequencies: http://www.math.cornell.edu/~mec/2003-2004/cryptography/subs/frequencies.html Decryption (known key): http://youtu.be/oHcJ4QLiiP8 Encryption: http://youtu.be/izFivfLjD5E

From playlist Cryptography and Coding Theory

Video thumbnail

Cryptography (part 1 of 3)

An informal introduction to cryptography. Part of a larger series teaching programming at http://codeschool.org

From playlist Cryptography

Video thumbnail

Exercise - Write a Fibonacci Function

Introduction to the Fibonacci Sequence and a programming challenge

From playlist Computer Science

Video thumbnail

Follow-up: Barbie electronic typewriter

Here is a copy of the description from the Barbie video: ---- I first found this story on the crypto museum website, which has great information about the Barbie typewriter (and other cipher machines) https://www.cryptomuseum.com/crypto/mehano/barbie/ ------- Thanks to Sarah Everett fr

From playlist My Maths Videos

Video thumbnail

Symmetric Key Ciphers

Cryptography and Network Security by Prof. D. Mukhopadhyay, Department of Computer Science and Engineering, IIT Kharagpur. For more details on NPTEL visit http://nptel.iitm.ac.in

From playlist Computer - Cryptography and Network Security

Video thumbnail

Live CEOing Ep 544: Language Design in Wolfram Language [Ciphers & WFR Submissions] [Part 01]

In this episode of Live CEOing, Stephen Wolfram discusses upcoming improvements and features to the Wolfram Language. If you'd like to contribute to the discussion in future episodes, you can participate through this YouTube channel or through the official Twitch channel of Stephen Wolfram

From playlist Behind the Scenes in Real-Life Software Design

Video thumbnail

Cryptography (part 2 of 3)

An informal introduction to cryptography. Part of a larger series teaching programming at http://codeschool.org

From playlist Cryptography

Video thumbnail

Shannons Theory (Contd...2)

Cryptography and Network Security by Prof. D. Mukhopadhyay, Department of Computer Science and Engineering, IIT Kharagpur. For more details on NPTEL visit http://nptel.iitm.ac.in

From playlist Computer - Cryptography and Network Security

Video thumbnail

What is Bill Cipher? (Scientific Analysis)

What is Bill Cipher? Today we discover the very very confusing science of what Gravity Fall's Bill Cipher is. =======WARNING VERY VERY CONFUSING======= This video talks about dimensions and alternate universes. Your mind might explode! Sources: -http://en.wikipedia.org/wiki/Four-dim...

From playlist Scientific Videos

Video thumbnail

Stream Ciphers

Cryptography and Network Security by Prof. D. Mukhopadhyay, Department of Computer Science and Engineering, IIT Kharagpur. For more details on NPTEL visit http://nptel.iitm.ac.in

From playlist Computer - Cryptography and Network Security

Video thumbnail

The Barbie electronic typewriter - with Just My Typewriter

I first found this story on the crypto museum website, which has great information about the Barbie typewriter (and other cipher machines) https://www.cryptomuseum.com/crypto/mehano/barbie/ ------- Thanks to Sarah Everett from Just My Typewriter, check out her channel here: https://www.y

From playlist My Maths Videos

Related pages

Cipher | List of ciphertexts | Substitution cipher