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From: Mok-Kong Shen on 7 Jul 2010 04:39

The following updates/combines some tiny humble ideas of mine,
expressed on diverse occassions sometime somewhere, in making the
classical polyalphabetic processing more complex, in the hope of
rendering it much harder for the analyst to work on (with attendant
higher computing cost, understandably).

We assume that the alphabet is coded in [0,25], that the user-given
substitution matrix is random (each column a pseudo-random permutation
of [0,25]) and that the given plaintext sequence is subdivided into
blocks of 26 in length. We define the following arrays:

M[26][26] the user-given substitution matrix (will be modified)
P[26] the plaintext
C[26] the ciphertext
KS[26] the key sequence, initialized by the message key (with
repetition, if needed)
S[26] auxiliary, initialized to 0 or with an user determined sequence

The algorithm runs as follows:

for (i=0; i<26; i++)
{ k=KS[i]; b=S[i];
u=P[i];
v=C[i]=(M[u][k]+b)%26;
w=(M[v][k]+b)%26;
t=M[u][k]; M[u][k]=M[v][k]; M[v][k]=M[w][k]; M[w][k]=t;
S[i]=(S[i]+w)%26;
KS[i]=w;
}

For comments and critiques I should be very grateful.

M. K. Shen
-----------------------------------------------------------------------

[OT] In an attempt to reduce annoyance to the general readers, I am
unfortunately forced to forgo any opportunities of discussion with
those, who have the unnice impulse (urge, "Drang" in German) to
overload their posts with bandwidth-wasting personal stuffs and/or
bad words, by placing them into my kill-file. Those who dislike my
posts for whatever reasons are requested to kindly put me into their
kill-files as well.
From: Mok-Kong Shen on 17 Jul 2010 03:38
Mok-Kong Shen wrote:
[snip]

[Addendum] It may be remarked that through dynamics we have
'straightforwardly' rendered the classical analysis technique of
polyalphabetic substitutions, which starts with the determination
of the length of the key, impossible for the simple reason that
we don't have a key of constant length at all. (This enormous
effect of dynamics is similar to the case of using dynamic keys
in block encryption which I have suggested in a few previous threads.)

M. K. Shen

From: Mok-Kong Shen on 22 Jul 2010 12:07

[Addendum2] One could of course on computer use an 8-bit alphabet and an
corresponding 256*256 matrix. One could also employ multiple encryption,
cascading e.g. the processing with two matrices in succession, using
thereby preferably two different initial keys that are unique for the
message.

M. K. Shen
From: Pubkeybreaker on 22 Jul 2010 14:33
On Jul 7, 4:39 am, Mok-Kong Shen <mok-kong.s...(a)t-online.de> wrote:

<snip>

> [OT] In an attempt to reduce annoyance to the general readers, I am
> unfortunately forced to forgo any opportunities of discussion with
> those, who have the unnice impulse (urge, "Drang" in German) to
> overload their posts with bandwidth-wasting personal stuffs and/or
> bad words, by placing them into my kill-file.

Translation: I want to spew nonsense without criticism and I will
ignore anyone
who does criticize it.
From: Mok-Kong Shen on 22 Jul 2010 16:46
Pubkeybreaker wrote:
> On Jul 7, 4:39 am, Mok-Kong Shen<mok-kong.s...(a)t-online.de> wrote:
>
> <snip>
>
>> [OT] In an attempt to reduce annoyance to the general readers, I am
>> unfortunately forced to forgo any opportunities of discussion with
>> those, who have the unnice impulse (urge, "Drang" in German) to
>> overload their posts with bandwidth-wasting personal stuffs and/or
>> bad words, by placing them into my kill-file.
>
> Translation: I want to spew nonsense without criticism and I will
> ignore anyone
> who does criticize it.

Translation: You should either use kill-file or shut up!

M. K. Shen

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