Systems and methods are provided for performing transactions and managing communications using a trusted third party. In one embodiment, a sender transfers an encrypted version of a file (such as a digitally encoded audio track, movie, document, or the like) to someone who wishes to receive it. The receiver computes a first hash of at least a portion of the encrypted data content, and sends the first hash to a third party configured to compare at least a portion of the first hash to at least a portion of a second hash. The receiver receives a file decryption key from the third party, and decrypts at least the portion of the received encrypted data content with the decryption key. In some cases, multiple hashes of the encrypted data content may be computed, each using a different portion of the encrypted data content.
