In recent years, blockchain has been attracting attention for its use in cryptocurrencies such as Bitcoin. In blockchain, it is important to verify the validity of data stored in blocks. Digital signatures are a technique used to verify the validity of data, and are also used in blockchains. In a multi-signature scheme, multiple signatures are generated by multiple people by each signing the data. Boneh et al. proposed a multiple signature scheme in which the signature length and the length of the public key do not depend on the number of signers. In this paper, we propose a new signature generation method
using a public key. In this paper, we propose a multiple signature scheme that reduces the computational complexity by dividing the signature generation process into several steps, which enables a single signer to perform the signature generation.