ID-Based Key-Insulated Electronic Cash System with Multiple Banks

The basic idea behind an ID-based cryptosystem is that user´s public key can be determined by his identity information. Comparing with the traditional certificate-based cryptography, ID-based cryptography can eliminate much of the overhead associated with the deployment and management of certificate. However, exposure of private keys can be the most devastating attack on a public key based cryptosystem since such that all security guarantees are lost. An ID-based key-insulated electronic cash system with multiple banks is presented. For solving the problem of key exposure of the basic scheme, the technique of key insulation is applied.