shishi_n_fold3

Arguments

Shishi * handle

shishi handle as allocated by shishi_init().

const char * in

input array with data to decrypt.

size_t inlen

size of input array with data to decrypt ("M").

char * out

output array with decrypted data.

size_t outlen

size of output array ("N").

Overview

Fold data into a fixed length output array, with the intent to give each input bit approximately equal weight in determining the value of each output bit.

The algorithm is from "A Better Key Schedule For DES-like Ciphers" by Uri Blumenthal and Steven M. Bellovin, http://www.research.att.com/~smb/papers/ides.pdf, although the sample vectors provided by the paper are incorrect.

Return value

Returns SHISHI_OK iff successful.