The authors first define the concept of a generalized group-oriented cryptosystem. Based on the generalized secret-sharing scheme proposed by H.Y. Lin and L. Harn (1991), they present a noninteractive approach for realizing such a group-oriented cryptosystem. There are three advantages to the approach: it does not need any trusted clerk or center to distribute the messages to the recipients in the receiving group; it allows the sender to renew the encryption/decryption keys for broadcasting secure messages in each transmission; and it allows the sender to determine the legal recipients without any coordination with the receiving groups. >
['Chin-Chen Chang', 'Horng-Chin Lee']
A new generalized group-oriented cryptoscheme without trusted centers