Abstract: Data being transmitted through a communications network can be protected by cryptography. In a data processing environment, cryptography is implemented by an algorithm which utilizes a secret key, or sequence of bits. Any key-controlled cryptographic algorithm, such as the Data Encryption Standard, requires a protocol for the management of its cryptographic keys. The complexity of the key management protocol ultimately depends on the level of functional capability provided by the cryptographic system. This paper discusses a possible key management scheme that provides the support necessary to protect communications between individual end users (end-to-end encryption) and that also can be used to protect data stored or transported on removable media.