I understand that "anagramming" is often used after frequency analysis of a traditional substitution cipher, but anagramming requires prior frequency analysis to provide a starting point. Is there any technique other than frequency analysis for a cipher-text only attack on a traditional substitution cipher?
Yes, there are many. Here are the few that I know:
- Brute-Force: Simply trying all possible keys.
- Kasiski examination: Exploiting the repeated words in the ciphertext to figure out the key length in Vigenere Cipher.
- Friedman test aka Kappa Test: Measures the unevenness of the cipher letter frequencies to break the Vigenere cipher.
- Key elimination: Eleminate the key by XORing two plaintexts with the same key.