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I am trying to figure out an encryption algorithm whose key schedule function seems to be similar to RC6. However, it seems to be creating S-Boxes using 16-bit integers instead of 32-bit ones. I have posted some pseudocode below which is filling the S-Box, S is an array of 16-bit values and so is S_, except S_ is 27 * sizeof(WORD) away from S (I'm guessing it's a "2D" S-box, sorry if my terminology is wrong).
The value of delta is 0x79B9.

for (int i{ SBOX_ROUNDS }; i > 0; i--)
{
    S[0] = S_[0] = ST_[-1] + DELTA;
    S_[0] = x;
    S++; S_++;
}

Does anyone know of an algorithm that could use this? I've been trying to find it for literally months now, but no success.
Thank you for taking the time to read!

e-sushi
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Prixar
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  • Hi Prixar and welcome. It's not deciphering a block of data, but that's a long shot; hoping that anybody recognizes that piece of code. – Maarten Bodewes Mar 23 '16 at 15:36
  • 0x79B9 are hex digits from Phi, used in the key schedule of TEA and Serpent, among others, as a full 32-bit value – Richie Frame Mar 23 '16 at 21:03

0 Answers0