An extended cryptographic key generation scheme for multilevel data security

S. Akl and P. Taylor (Proc. Crypto-82, p.237-250, 1982) proposed an elegant solution to the multilevel key distribution problem, using a cryptographic approach. In the present work, two problems associated with the Akl-Taylor scheme are considered. First, a time-memory tradeoff technique to overcome the problem of the extremely large memory space required by the Akl-Taylor scheme is proposed. Second, an extended scheme that localizes within a small region as much as possible the inserting/deleting problem associated with the Akl-Taylor scheme is proposed