초록 ▼

A key distribution method and system are disclosed in which a sender and receivers share a common key information for performing a secure broadcast communication. By use of a center side apparatus, a center generates key information of a receiver in association with a subset inclusive of two or more

A key distribution method and system are disclosed in which a sender and receivers share a common key information for performing a secure broadcast communication. By use of a center side apparatus, a center generates key information of a receiver in association with a subset inclusive of two or more elements of a proper finite set S1 on the basis of a space determined by a subset inclusive of two or more elements of another finite set S2. A sender side apparatus, a sender makes the multi-address transmission of key distribution data W inclusive of data generated corresponding to each element of the finite set S1 and data generated corresponding to a set of plural receivers through a communication network. By use of a receiver side apparatus, a receiver generates common key information between the sender and the receiver from the key distribution data W and the key information of the receiver.

대표청구항 ▼

[ We claim:] [1.] A key distribution system in which a sender and a plurality of receivers use individual key information generated beforehand by a key generator to share a common key information for performing a secure broadcast communication, wherein(i) the key generator side is provided with:mean

[ We claim:] [1.] A key distribution system in which a sender and a plurality of receivers use individual key information generated beforehand by a key generator to share a common key information for performing a secure broadcast communication, wherein(i) the key generator side is provided with:means for generating confidential information of a receiver in association with a subset inclusive of at least two elements of a first finite set S1 on the basis of a space determined by a subset inclusive of at least two elements of a second finite set S2; andmeans for distributing said confidential information to the receiver,(ii) the sender side is provided with:means for generating key distribution data corresponding to each element of said first finite set S1; andcommunication means for making the multi-address transmission of said key distribution data,and (iii) the receiver side is provided with:storage means for storing said confidential information beforehand; andmeans for calculating common key information K between the sender and the receiver from the stored confidential information for each receiver and the key distribution data.