A system and method for communicating information between a first party and a second party, comprising identifying desired information, negotiating, through an intermediary, a comprehension function for obscuring at least a portion of the information communicated between the first party and the second party, communicating the encrypted information to the second party, and decrypting the encrypted information using the negotiated comprehension function. Preferably, the intermediary does not itself possess sufficient information to decrypt the encrypted information, thus allowing use of an "untrusted" intermediary. The comprehension function may be dynamic with respect to its response to the negotiated comprehension function, and thus permit limitations on the use of the information by the second party. For example, the decryption of the encrypted information may be time limited.