Modern cryptography can make it virtually impossible to decipher documents without the cryptographic key thus making the availability of the contents of those documents depend on the availability of the key. This article examines the Fourth and Fifth Amendments' protection against the compulsory production of the key and the scope of the Fifth Amendment immunity against compelled production. After analyzing these questions using prevailing Fourth and Fifth Amendment jurisprudence, I shall describe the advantages of a privacy-based approach in practical and constitutional terms. [excerpt]
Greg S. Sergienko, Self Incrimination and Cryptographic Keys, 2 Rich. J.L. & Tech 1 (1996). Available at: https://scholarship.richmond.edu/jolt/vol2/iss1/3.