Globalization of the Internet has boosted electronic information exchange on both the personal and business levels. The popularity turned information communication and secure Internet transactions, which require the verification of digital signatures and identities, into a hot issue. Most existing digital signature schemes are based on the public key system of RSA and ElGamal. Security thus depends on solving factorization and the discrete logarithm. However, the encryption–decryption key of the RSA is too large, and the signature authentication of ElGamal takes too long, making this method unsuitable for certain systems. Additionally, the superior security and efficiency of the elliptic curve cryptosystem (ECC) [11], [12] and [13] provides an imperative application foreground. This study integrates the short secret key characteristic of the elliptic curve cryptosystem and the (t, n) threshold method to create a signature scheme with simultaneous signing. The distinguishing feature of the proposed scheme is that the threshold value denotes the minimum number of members required to produce a valid group signature. All message recipients then can verify the signature.