for i in {0..25}; do echo "Ackkmaa" | /usr/games/bin/caesar $i ; done * Substitution can be cracked using Cryptool using letter frequency, digram/trigram frequency and word frequency but a large portion of text must be given as input * Vigenere can also be cracked using Cryptool (for English and German texts) * **Xor** / **Vernam** * Strings/files xored with a random key cannot be cracked if length(key) == length(text) * If length(key) %% << %% length(string) **xortool** can be used to infer key length and possible keys given the most common byte: (0x20 for text and 0x00 for binary) * Autocorrelation can be used in Cryptool as well ==Tools for analysis== * Cryptool (preferably v1.0) [[http://www.cryptool.org/en/cryptool1-en]] * xortool [[https://github.com/hellman/xortool]]