Research on secure proxy signature schemes on the practical environment

Abstract

Since some years ago, the digital signature has prevailed in the world. With the help of the Public Key Infrastructure (PKI), many applications employ the digital signature to authenticate a user or a system. In the digital signature, a user can digitally sign a document with a private key that is only known to the user. The digital signature can be verified by the public key which corresponds to the private key used to generate the digital signature. Since it is computationally infeasible to generate a users digital signature without the private key of the user, it is convinced that only the owner of the private key can generate a valid digital signature. Recently, the importance of the right delegation between the entities has been an increase. The representative applications to require the delegation facility is computational grids and a digital right management system. In the computational grids, a dynamic delegation is required because many agent nodes in the distributed environment should access an entitys resources to execute the entitys job on behalf of the entity. In the digital right magement system, the delegation facility is required for a specific device to share a digital content with the other devices that belong to the owner of the specific device. For the above cases, the proxy signature can be a good solution to support the delegation facility. The concept of proxy signature, introduced by Mambo, Usuda and Okamoto in 1996, provides a method for a right grantor, or an original signer, to delegate signing capabilities to a right grantee, or a proxy signer, and enables the right grantee to sign a message on behalf of an original signer within a given context. Until so far, a number of proxy signature schemes have been proposed and analyzed. However, due to the lack of the applications to use the dynamic delegation facility, the research of the proxy signature scheme has been just concentrated on theoretical design and analysis under ...