Although the Digital Rights Management (DRM) systems have been rapidly developed to protect copyrights, they have not considered user privacy because they regard this as an unnecessary element in achieving their goals. However, the protection of user privacy becomes one of the most important issues in DRM systems as the number of people who suffer from accidents caused by the infringement of individual information dramatically increases. This paper suggests a license management protocol which is a more powerful protocol to protect individual information in DRM. To protect the exposure of information of user identification, the proposed protocol uses alias like a TID and a token instead of the identity of content users. Due to using alias, this protocol can guarantee the anonymity of content users. Also, it can prevent the leakage of individual information through encryption of usage information. In this way, it can protect the privacy of content users.

Mobile ad-hoc networks consist of mobile nodes interconnected by multihop path that has no fixed network infrastructure support. Due to the limited bandwidth and resource, and also the frequent changes in topologies, ad-hoc network should consider these features for the provision of security. We present a secure routing protocol based on identity-based signcryption scheme. Since the proposed protocol uses an identity-based cryptosystem, it does not need to maintain a public key directory and to exchange any certificate. In addition, the signcyption scheme simultaneously fulfills both the functions of digital signature and encryption. Therefore, our protocol can give savings in computation cost and have less amount of overhead than the other protocols based on RSA because it uses identity-based signcryption with pairing on elliptic curve. The effectiveness of our protocol is illustrated by simulations conducted using ns-2.