Light-weight authentication and billing in mobile communications

We present an efficient scheme for mobile devices to conduct transactions demanding high security. The use of cryptographic mechanisms is minimized by applying block-ciphers and one-way hash primitives, which can be operated with low-end processors and very little working space. Undeniable billing can be achieved by applying one-way hash chains. Owing to one-way hash functions, the integrity of the masked transactions and the billing information can be verified, even when the masked information is transmitted in public. Complicated cryptographic mechanisms, also the regulations among roaming countries, thus can be eliminated so that a light-weight billing can be achieved.