Here's the challenge:
OK, two challenges, one harder (perhaps) than the other. I created two files, xyz and babychallenge. The plaintext for the files are somewhat similar.
Both are composed mostly of one ASCII character with an additional sentence or two in English.
They are available here:
The SHA1 checksums for these two files are:
// // // File Checksum Integrity Verifier version 2.05. // af20e99ecc9284b7b91195cb6603d050 xyz
// // // File Checksum Integrity Verifier version 2.05. // 403b4b109a628d3befe29be942c8f909 babychallenge
The plaintext and options file for these are no longer on my computer system.
Perhaps my inability to figure out how one would decrypt Yull-encrypted files without all the parameters only shows my ignorance of cryptography. Perhaps but perhaps not. The files both pass the NIST test for randomness.
With Yull I have strived to make it easy to protect your data and near impossible for an adversary to retrieve it without your cooperation.
I think I have succeeded, but of course, I cannot prove a negative.
You can read the White Paper here on the web site to learn how Yull works. Perhaps that's some help.
PROVE ME WRONG! SHOW ME YULL IS A FAILURE!
I will answer questions (if they are useful for the rest of the community) about these files.