Tag Info

Enigma is not a Feistel cipher. A "Feistel cipher" is a block cipher with a specific structure, namely the whole business with the two halves, the combination of one half with a (one-way) function of the other half and a reversible operation (e.g. XOR), and the swap. See the Wikipedia page which has nice schematics. So considering Enigma as a kind of ...

Sorry to ask this, but did you try a web search? The first hit has many links to enigma simulation source code. For example, this.

No, it's a rotor machine and more importantly, a stream cipher that operates on a character-by-character basis. Block ciphers operate on a chunk at a time. Feistel ciphers are a way to construct block ciphers. We could talk more about Feistel ciphers or more basically block ciphers, but that's not your question. At its most basic, Enigma is a stream cipher ...

According to "Applied Cryptanalysis", the theoretical keyspace of Enigma is approximately $2^{366}$, but due to practical limitations, Enigma as used by the Germans only had a keyspace of approximately $2^{77}$. Given the power of some of the clouds out there (with GPUs and all), I bet you could do a brute-force attack of the 77-bit key space in a reasonable ...