Use of simple schemes
in [Cryptography]
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From: Mok-Kong Shen on 26 Nov 2009 05:10 Mok-Kong Shen wrote: > I suppose that in crypto computations, like in the general case of > numerical mathematical computations, there is always a trade-off > between computing cost and complexity of computing procedure employed. > I mean that, since now computing cost is often a minor issue, one > could, as an alternative to applying sophisticated algorithms that > require deep analysis in their design and much care in implementation, > employ certain simple primitive procedures, using a much higher number > of steps of operations to compensate for their inherent weakness with > respect to the complex procedures underlying the sophisticated > algorithms. I like to mention two further schemes which could be viable candidates for the above considerations. The first goes back in my knowledge to a thesis done decades ago by someone at MIT (I forgot his name, but his work was discussed in the group), namely employing Hufman encoding but randomly assigning 0/1 to the branches emanating from each node of the tree. Since we here assume that we could be quite generous in employing computing resources (CPU, storage, transmission), we could generate a squence of random Hufman trees (without consideration of the compression efficiency, with random assignments of 0/1) and use each tree to only encrypt a few (a chosen small fixed number, or else determined pseudo-randomly) plaintext units. The second is a humble scheme suggested by me years ago: Choose a positive value p leas then 1. Output with probability p an (with an pseudo-random bit xor) encrypted plaintext bit and with probability 1-p output a (dummy) pseudo-random bit. Under our current assumption of sufficiently cheap computing resources, we could choose p to be a very small value in order to correspond to a high level of desired security. Thanks, M. K. Shen
From: Mok-Kong Shen on 26 Nov 2009 11:08 Mok-Kong Shen wrote: [snip] > ....... Choose > a positive value p leas then 1. Output with probability p an (with an > pseudo-random bit xor) encrypted plaintext bit and with probability > 1-p output a (dummy) pseudo-random bit. ..... I am afraid that wasn't very clear. Please read the 2nd sentence as "With the help of a PRNG output pseudo-randomly with probability p ...." M. K. Shen
From: Greg Rose on 26 Nov 2009 11:20 In article <hem96k$chq$00$1(a)news.t-online.com>, Mok-Kong Shen <mok-kong.shen(a)t-online.de> wrote: >M. K. Shen Mok-Kong is talking to himself again. This is a good sign, soon he will get bored with the conversation. Greg. -- Greg Rose 232B EC8F 44C6 C853 D68F E107 E6BF CD2F 1081 A37C
From: Mok-Kong Shen on 26 Nov 2009 17:26 Greg Rose wrote: > In article <hem96k$chq$00$1(a)news.t-online.com>, > Mok-Kong Shen <mok-kong.shen(a)t-online.de> wrote: >> M. K. Shen > > Mok-Kong is talking to himself again. This is a > good sign, soon he will get bored with the > conversation. Nice to know that you "did" respond to my post.
From: Spinner on 27 Nov 2009 14:18
Mok-Kong Shen <mok-kong.shen(a)t-online.de> wrote: >Greg Rose wrote: >> In article <hem96k$chq$00$1(a)news.t-online.com>, >> Mok-Kong Shen <mok-kong.shen(a)t-online.de> wrote: >>> M. K. Shen >> >> Mok-Kong is talking to himself again. This is a >> good sign, soon he will get bored with the >> conversation. > >Nice to know that you "did" respond to my post. Not true. Nobody is responding. You are making all of this up, and so are we. Personally, I'm planning to wake up soon and the movie will be over and i'll pick up my popcorn and coke and go home. -- 2+2!=5 even for extremely large values of 2 |