A book cipher, or Ottendorf cipher, is a cipher in which the key is some aspect of a book or other piece of text. Books, being common and widely available in modern times, are more convenient for this use than objects made specifically for cryptographic purposes. It is typically essential that both correspondents not only have the same book, but the same edition. Traditionally, book ciphers work by replacing words in the plaintext of a message with the location of words from the book being used. In this mode, book ciphers are more properly called codes. This can have problems; if a word appears in the plaintext but not in the book, it cannot be encoded. An alternative approach which gets around this problem is to replace individual letters rather than words. One such method, used in the second Beale cipher, replaces the first letter of a word in the book with that word's position. In this case, the book cipher is properly a homophonic substitution cipher. However, if used often, this technique has the side effect of creating a larger ciphertext (typically 4 to 6 digits being required to encipher each letter or syllable) and increases the time and effort required to decode the message. (Wikipedia).
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
An informal introduction to cryptography. Part of a larger series teaching programming at http://codeschool.org
From playlist Cryptography
From playlist Week 2 2015 Shorts
Cryptanalysis of Classical 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
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
Cryptograph: Substitution Cipher (Caesar Cipher)
This lesson explains how to encrypt and decrypt a message using a Caeser cipher. Site: http://mathispower4u.com
From playlist Cryptography
An informal introduction to cryptography. Part of a larger series teaching programming at http://codeschool.org
From playlist Cryptography
Cryptography I, Lecture 1: Classical ciphers
From playlist Crypto1
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
Cryptography is fascinating because of the close ties it forges between theory and practice. It makes use of bitwise computations, advanced algebra, string operations and everything in between. Explaining cryptography requires not only showing the math behind it, but also tying it to real-
From playlist Wolfram Technology Conference 2021
Cryptography: Transposition Cipher
This lesson explains how to encrypt and decrypt a message using a transposition cipher. Site: http://mathispower4u.com
From playlist Cryptography
How Encryption Keeps Your Data Safe
Start protecting yourself on the web at https://NordVPN.com/SCISHOW or use code SCISHOW to save 75% off of a 3-year Virtual Private Network plan, plus 1 month free. Keeping our data safe and secure is necessary in today's world, but a lot of the encryption we depend on has been in devel
From playlist Uploads
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
Cryptography I Intro to Stream Ciphers
From playlist Crypto1
Cryptography I Intro to Stream Ciphers
From playlist Crypto1
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
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
ADFGVX Cipher: Encryption and Decryption (Updated)
Encryption and Decryption of the World War One ADFGVX Cipher, through examples. This video replaces an earlier one with the same content, but has some improvements and corrections. #cryptography
From playlist Classical Cryptography