Some of Kleiman's most notable work took place at S-doc where his role was Chief Information Security Officer. While there he developed a Windows encryption tool that surpassed NSA, NIST, and Microsoft Common Criteria Guidelines. This technology was used at NASA, U.S. Dept. of Treasury, Office of the Inspector General, and the US Post Office. Cryptography was routinely used at S-doc to develop several products, broadly aimed at the reliable and verifiable transmission of data and messages, centered around the idea of an "unalterable, encrypted audit log system".