An apparatus includes a tokenizer and a validator. The tokenizer divides a file into first, second, and third portions. The tokenizer also encrypts the first, second, and third portions using a first key to produce first, second, and third tokens. The validator receives a fourth token with a signature of a first user and receives a fifth token with a signature of a second user. The validator also combines the first token, the fourth token, and the fifth token to produce a second key and determines whether the second key matches the first key. If the second key does not match the first key, the validator communicates an alert indicating that the first key does not match the second key. If the second key does match the first key, the validator decrypts first, fourth, and fifth tokens to reproduce the file.