Electronic Cash Protocol Using the Magic Ink Signature

매직 잉크 서명 기법을 이용한 전자 현금 프로토콜 설계

Chaum's blind signature scheme is the typical withdrawal procedure of electronic cash. In blind signature scheme, a signer sign a document while he never knows the content of the signed document. Yung and Jakobsson presented new signature scheme with which the content of document can be unblinded if unusual activity is detected. This signature is referred to as the magic ink signature. In this paper, we analyze the magic ink signature, and present two new magic ink signature schemes using KCDSA and Schnorr signature algorithm. We propose two types of the efficient electonic cash system using these magic ink signature schemes. One is the electronic cash system with a single server magic init signature scheme, and the other is the electronic cash system with a distributed magic ink signature scheme.