Re: An hash-Encryption algorithm

Kristian Gjøsteen <kristiag+news@xxxxxxxxxxxx> wrote in news:vv0qa3-
pll1.ln1@xxxxxxxxxxxxxxxxxxxxx:

> Neo <neoscandal@xxxxxxxxx> wrote:
>>K(0) = user entered key + salt (which is added plainly into the
>>encrypted file header)
>>
>>K(1) = MD5(K(0))
>>
>>C1 = K(1) XOR P1
>>
>>for n = 2 onwards..
>>
>>K(n) = MD5( K(n-1) + C(n-1)) <----------ciphertxt f/b
>>C(n) = K(n) XOR P(n)
>>
>>Provided the attacker has ONE (Cn,Pn) pair.. n = 1 or n != 1 .. what are
>>the attacks possible.
>
> Come on! If you can't figure it out from the equations you already
> have there, you aren't trying hard enough.
>

Oh yes. Hmm.. another revision

What if from n=2 onwards K(n) = MD5( K(n-1) + C(n-1) + user entered key).
theres no way the attacker can obtain the key.. even given both P1 and C1.

Or have i missed something again.
.

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