From 398a6e2e111d101632f169346ba5f0fc5bf60113 Mon Sep 17 00:00:00 2001 From: Harshil Date: Sun, 14 Aug 2016 01:00:20 +0530 Subject: [PATCH] Update README.md --- README.md | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/README.md b/README.md index 1aaa5898d..4a28a8b57 100644 --- a/README.md +++ b/README.md @@ -82,13 +82,17 @@ Add comments here ## Ciphers ### Caesar -![alt text][caesar] +![alt text][caesar]
In cryptography, a **Caesar cipher**, also known as Caesar's cipher, the shift cipher, Caesar's code or Caesar shift, is one of the simplest and most widely known encryption techniques.
It is **a type of substitution cipher** in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet. For example, with a left shift of 3, D would be replaced by A, E would become B, and so on.
The method is named after **Julius Caesar**, who used it in his private correspondence.
The encryption step performed by a Caesar cipher is often incorporated as part of more complex schemes, such as the Vigenère cipher, and still has modern application in the ROT13 system. As with all single-alphabet substitution ciphers, the Caesar cipher is easily broken and in modern practice offers essentially no communication security. ###### Source: [Wikipedia](https://en.wikipedia.org/wiki/Caesar_cipher) +### Transposition +In cryptography, a **transposition cipher** is a method of encryption by which the positions held by units of plaintext (which are commonly characters or groups of characters) are shifted according to a regular system, so that the ciphertext constitutes a permutation of the plaintext. That is, the order of the units is changed (the plaintext is reordered).
+Mathematically a bijective function is used on the characters' positions to encrypt and an inverse function to decrypt. +###### Source: [Wikipedia](https://en.wikipedia.org/wiki/Transposition_cipher) [bubble-toptal]: https://www.toptal.com/developers/sorting-algorithms/bubble-sort [bubble-wiki]: https://en.wikipedia.org/wiki/Bubble_sort [bubble-image]: https://upload.wikimedia.org/wikipedia/commons/thumb/8/83/Bubblesort-edited-color.svg/220px-Bubblesort-edited-color.svg.png "Bubble Sort"