Re: Confirmation of Shannon's Mistake about Perfect Secrecy of One-time-pad

On Oct 28, 9:38 pm, wangyong <hell...@xxxxxxx> wrote:
On 10 29 , 12 24 , William Hughes <wpihug...@xxxxxxxxxxx> wrote:

On Oct 28, 9:50 am, wangyong <hell...@xxxxxxx> wrote:

When only considering C=0 and the cryptosystem
(regardless of the prior probability of plaintext),
we can educe that the plaintexts are equally likely

Are you now admitting this statement is false?

================================When only considering C=0 and the
cryptosystem
(regardless of the prior probability of plaintext),

can you see the precondition?

You have agreed

A: No observation on the cyphertext gives you
any information about the probablility distribution
on the plaintext,

Even when not considering a prior probability
on the plaintext ("regardless of the prior
probability of plaintext") the observation of the
value of the cyphertext tells you nothing about
the probability distribution on the plaintext.
In particular, you cannot "educe that the plaintexts
are equally likely"

- William Hughes

"educe that the plaintexts

are equally likely"

you should know the probability is under imperfect conditions , the
posterior is under complete conditions.The probabilities are not the
same.



Your "prior condition" is that before noting that C=0 you know
nothing about the probability distribution on
the plaintext. You then note that C=0, an observation
that gives you no information about the probability
distribution on the plaintext. You then conclude
that the probability distribution on the plaintext is
uniform.

- William Hughes


.

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