Very possible I've misunderstood to process, but given the hash is produced via the reuse of the secret key and that the crypto uses a one-time pad - why is it

Very possible I've misunderstood to process, but given the hash is produced via the reuse of the secret key and that the crypto uses a one-time pad - why is it not possible to crack the secret key? EDIT: For an explanation of how this might be done, see: http://crypto.stackexchange.com/questions/2249/how-does-one-attack-a-two-time-pad-i-e-one-time-pad-with-key-reuse http://crypto.stackexchange.com/questions/2249/how-does-one-...