New answers tagged stream-cipher
Most advantages have to do with the fact that it includes authentication. For example: An authenticated encryption primitive is easier to use correctly. Only a single primitive that has to be secure. One pass over the data to both encrypt and authenticate may be faster. (Bernstein's rebuttal is that a separate MAC allows faster detection of forgeries, ...
It is incorrect that Wikipedia does not mention other stream ciphers than the synchronous ones. It also mentions asynchronous ones (that is, where the keystream depends on the previous ciphertexts -- and thus, the previous plaintext) together with associated advantages: this allows re-synchronisation of the sending and receiving end. Additionally, an ...
It is my understanding that a pre-agreed astronomical noise source with a protocol presenting a few sync bytes would do the job. Nobody records enough astronomical noise with telescopes to have a good chance of having recording your source. However: if somebody happened to record it that day, you're sunk.
Well, one way to look at this is to notice that, if the feedback polynomial is prime, then the result of starting with state $E$, and then stepping the LFSR forward $N$ steps is the value $2^N \cdot E$, where we do the computation in $GF(2^K)$, using the polynomial representation (with the feedback polynomial being the polynomial). In addition, I believe ...
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