Efficient and Adaptively Secure Append-Only Signature

Most of digital signatures require the secret key when signing a message, however, there does exists a kind of signature scheme which is able to sign by appending new message only, so-called append-only signature (AOS). Motivated by its numerous useful applications in network security such as secure routing, etc., in this paper, we propose new efficient AOS scheme with shorter public key (parameters) using ID- based cryptographic techniques. To our surprise, it is the first time to achieve a practical, adaptively secure AOS via ID-based encryption approach. The proposed signature enjoys the merit of security against adaptive attack, while the previously presented AOS is only secure in a weak sense of selective unforgeability. Finally, we also present a new restricted AOS (RAOS) signature, which may be of independent interest in practice.