OTP / XOR Split two encrypted texts that have the same key

Question

How can I crack two encrypted texts that used the same key twice? For example, plaintext1uses a key "abcdefg", but plaintext2uses a key "abcdefg".

I know that ciphertext2 ^ ciphertext1equally plaintext1 ^ plaintext2. And the hacking method plaintext1 ^ plaintext2is the same hacking method for the "book cipher" (also sometimes called the "running key"), although the running key cipher does not match the book cipher, right?)

I know that I should use a dictionary attack, but I'm not sure which dictionary / word list I should use, and the algorithm used to crack it. Can someone provide me with a link or some code that shows how to hack it?

I am new to cryptography and I just wanted to do it for fun. Can someone help me? Thank.

Answer 1

The most common attack is the “slip” of a common (but not too short) word XORagainst consecutive positions in the combined stream. If the word was used in one thread, XOR (usually) creates readable text for another thread.