Escrowable Authenticated Key Agreement Protocol

With the rapid development of the Internet, normal people’s life is becoming more and more concerned with all kinds of information, and more and more convenient. However, the Internet is an open system, and malicious organizations or individuals may want to use these large amounts of information to do bad things. How to assure the security of information in this open system has become a significant problem. Cryptography is an important and powerful means to assure information security in nowadays. Cryptography cannot work without keys, thus key management is a very important branch of cryptography.The goal of key management is not just to generate a key, but also to protect the key to be secure. The topic of this paper is to study how to safely manage the keys. We focus on one important part—authenticated key agreement protocols. In this paper, we will review the development process of key agreement protocols, and introduce authenticated key agreement protocols with various techniques for authentication. Also, we will summarize some security models during the development of key agreement protocols.In some specific scenarios, we may require that a session key is escrow-able, which means it should be known to some trusted third party. While in digital signature, another major branch of cryptography, we need to make sure that one’s signature cannot be forged, which requires the keys to be secret. To solve this problem, we usually use two certificates for one user. In traditional certificate scheme, a public key is corresponding to one private key. We have to use two certificates to meet the two requires. And this increases the burden of PKI’s management of certificate and the burden of user’s storage.Recently, escrow-able public-key encryption has been proposed. In escrow-able public-key encryption, one user can own one public key. corresponding to two private keys. One private key is only hold by the user, and the other private key can be escrowed by a third party. While encrypting, the user may use the escrowed key to achieve the goal that it’ll be escrowed. While signing a signature, it’11 use the private key known only by himself to make sure that the signature cannot be forged. And this kind of encryption does reduce the burden of PKI’s management and user’s storage.In this paper, we will introduce two escrow-able public key encryption schemes. And inspired by them, we design and propose two new authenticated key agreement protocols which are escrow-able. By analyzing the efficiency and security of the protocols, we conclude that these two protocols are computationally efficient and secure in some model.And the meaning of our protocols is that they do have the function that session keys can be escrowed. At the same time, they insure the signature cannot be forged.