Re: Key entropy, stream entropy, block entropy, block population entropy AKA uniique stream length

On 8 Feb, 18:05, Kristian Gjøsteen <kristiag+n...@xxxxxxxxxxxx> wrote:
<j...@xxxxxxxx> wrote:
There can
only be one stream for any key just as you say, but given a chosen
plaintext attack i do not beleive you can assert that you have the
first block in the keystream can you?

Of course you have the first part of the keystream. In a chosen plaintext
attack, you have the _entire_ key stream. That's in theory. In practice,
you typically know the start of the key stream because the start of the
message typically contains known or guessable plaintext.

--
Kristian Gjøsteen

OK, i agree you have the first part you know this area.
But that doesn't mean i have to use the first blocks of the PRNG
OUTPUT.

Jonas Thörnvall

.

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