A public-key cryptosystem suitable for digital multisignatures (Japanisch)

The public-key cryptosystem presented by Rivest and his group has public-key and signature functions. However, in affixing multiple signatures on one document, the message length and the number of blocks increase. This paper presents a public-key cryptosystem which allows multiple signatures to be affixed on one document without increase in message length and the number of blocks. This technique provides a practical means for implementing security of electronic document information systems.