Detachable Electronic Coins

We propose a non-divisible electronic cash system that combines the restrictive blind signature technique and a batch signature scheme based upon the binary tree structure. Contemporary electronic cash solutions rely on the divisibility paradigm to achieve significant computational savings, and such techniques are considered to be the most efficient. We demonstrate an alternative approach that employs batch cryptography to withdraw and spend multiple coins. This approach provides a set of alternative primitives for an electronic cash system that possesses comparable efficiency to the most efficient divisible based schemes.