Abstract:Key escrow systems have gained much attention in recent years. A key escrow system can provide cryptographic protection to sensitive data ,while at the same time, allows for the decryption of encrypted message under lawful authorization. Since the public were not satisfied with the classified encryption method used in key escrow system in hardware, such as Clipper and Capstone, NIST of US announced a cooperative program with industry to explore the possibilities of performing key escrow cryptography using software-only techniques. This paper proposes a scheme for supporting the implementation of key escrow systems in software, which employs symmetric encryption algorithm for securing communication, and one-way hash function and asymmetric cryptography for identifying the users and verifying session key.