Category Archives: Crypto

Secret splitting

A few days ago I resurrected all my files from a desktop system I haven’t used for almost six years. Below is my implementation of secret splitting as described in Bruce Schneier’s book “Applied Cryptography, 2nd edition”.

The idea is basically: generate a random keystream, xor the plaintext with the random keystream, use separate couriers and send the random keystream and the ciphertext to the final destination using separate routes, and finally combine the random keystream with the ciphertext to recreate the plaintext. None of the couriers know which piece they are carrying.

To improve this idea would be to generate more than one random keystream, xor the keystreams and the plaintext, thus requiring more couriers and different routes for each datastream.

And, by the way, xor crypto isn’t really that strong. Continue reading Secret splitting