1. A non-transitory computer-readable medium storing program instructions that, when executed by a processor included in a computer system associated with a first party, cause the first party computer system to perform a method for decrypting data content, the method comprising: receiving encrypted data content from a second party; computing a first hash of at least a portion of the encrypted data content; sending the first hash to the second party, wherein the second party is configured to compare at least a portion of the first hash to at least a portion of a second hash; receiving a decryption key from the second party; and decrypting at least the portion of the received encrypted data content with the decryption key, wherein computing the first hash of a portion of the encrypted data content comprises the first party computer system computing multiple hashes of the encrypted data content, where each of the multiple hashes is computed using a different portion of the encrypted data content.