I know this sounds weird, but I am actually looking for a cryptographic function that is the easiest/fastest to cryptanalize, and preferably one can find out the original message with a big accuracy.
why? if this is possible, then the "why" is classified :) if you're really interested I can let you know provided that:
- this is not possible
- or, whatever I want to do with it is "safe". legally speaking :)
(I've got fancy ideas, about 0.0000...01% of them actually work). so I don't expect much of this but hopefully, from what I remember from my cryptographic study a few years back, this is somewhat possible.
down to business.
- I have a short message.
- This message will be crypted using a very bad function so that it can be reconstructed at best possible accuracy. this step is crucial. time of operations is irrelevant. 100% accuracy is the target
- the cryptographic key has quite a few restrictions (which in this case is good) like: only printable characters, etc. I can't get into too much details because of the "why".
- the key cannot be touched in regards of how it should look. it will look in some way with quite a few restrictions
- the message however, CAN be touched. so, I can use the same key to crypt 10 messages (upto a billion. kidding :) upto any number you want), if that helps. It would be nice if this can be acieved with only one pass, but it's not a requirement.
- youj can consider a message to be as long as the key, or a few times longer. it doens't matter. again, the "why" allows me to do this any way I want it, so just ignore the fact that it's weird.
example.
key = abcd
message = 1234
or
message = 1234 5678 90we etc
I don't care. BUT, the message can contain absolutely ANY character. and in real life, it willd efinetly contain any characters (think of binary (as in non-ascii/printable) data if that helps).
so, from what I remember, based on restrictions on the message and the key, plus patterns due to using the sae key many times, a message can be decoded provided you don't know either the key or the message. and probably there are other cryptanalitical methods to descifer a message.
what I want from you experts, is the crypt function (like say xor, or rsa or whatever) and how to descifer the message. if you provide code for it, even better. but please do post the chances of correctly descifiring the entire message and what are the requirements for that to happen. I might be able to mess with the key as well, but not too much.
or just tell me what's the best choice of input in order to get my desired behaviour: a very bad encryption. maybe I'll be ablde to adjust both the message and key to suit it.
again, I cannot tell you the "why" but it will not be for data protection (duuh). It's just some alien idea I got one night which I do hope to include in the 0.000...0001% cases :).
I could do the research myself, but time does not allow me to venture in whild goose chaces anymore. (after all I spet about a year on the RSA challange before they closed it, trying to implement another alien idea of mine; which might just work, but since the challange is closed I figure someone beat me to it)
so lets get the discussion started and we'll see how we go further.
just assume I'm a noob on this matter. I forgot a lot of the notions anyway plus that a few months of a university cyptographic and cryptanalysis class is not much (and some minor research on my own, again, not much)
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