Password-based mechanism is the widely used method for authentication since it allows people to choose their own passwords without any assistant device to generate or store. However, people are used to choose easy-to-remember passwords such that guessing attacks could succeed. In 1992, Bellovin and Merritt proposed Encrypted Key Exchange (EKE) protocols for preventing guessing attacks, in which two communication parties A and B securely share a possibly weak password in advance. In large communication environments, it is inconvenient in key management that every two communication parties mutually share a secret. Three-party EKE protocols, in which all parties (clients) share their secrets with a trusted server only, are more suitable for large communication environments. In 1995, Steiner, Tsudik and Waidner proposed a realization of three-party EKE protocol which is later demonstrated that it is vulnerable to undetectable on-line guessing attacks. In this paper, We will show a new off-line guessing attack on Steiner, Tsudik and Waidners' protocol. Besides, we will also propose a new three-party EKE protocol which not only is secure against both the off-line guessing attack and undetectable on-line guessing attacks but also satisfies the security properties of perfect forward secrecy and known-key security.

Three-party encrypted key exchange: attacks and a solution

Service resource items for use in call setup in a telephone system are held on servers that are connected to a computer network which is logically distinct from the telephone system infrastructure; this computer network may, for example, make use of the Internet. Each service item is locatable on the network at a corresponding URI and is associated with a particular telephone number. A mapping is provided between telephone numbers and the URIs of associated service resource items. When it is desired to access a service resource item associated with a particular telephone number, this mapping is used to retrieve the corresponding URI which is then used to access the desired service resource item.

Method for Accessing Service Resource Items That are For Use in a Telecommunications System

Secure key agreement protocols for three-party against guessing attacks

A communication-efficient three-party password authenticated key exchange protocol

Security weakness in a three-party pairing-based protocol for password authenticated key exchange

An Improvement of the Password-Based Authentication Protocol (K1P) on Security against Replay Attacks

We propose a new authentication and key distribution protocol which is adaptable and reliable for communication networks. The secrets for authentication, which are chosen from a relatively small space by common users, are easy to guess. Our protocol gives a solution to protect the weak secrets from guessing attacks. Compared with other related work, our protocol is more reliable because it is resistant to various kinds of attacks including guessing attacks, and more adaptable because it reduces several overheads which make the existing protocols more expensive. We show how to apply our protocol to the Q.931 calling sequences and to the World Wide Web model.

An adaptable and reliable authentication protocol for communication networks

We design a feature interaction manager (FIM) used in the AIN switching system. We design and implement FIM module to handle service feature interactions in SSP. First we analyze the causes of service feature interactions, and on the basis of the result we suggest a technique with which interactions are detected and resolved in an execution environment. We designed the FIM block and implemented it on the SSP platform. The compatibility test was done successfully.

Design of service feature interaction manager in AIN

We design a feature interaction manager (FIM) used in the AIN switching system. By analyzing the interactions between features that have been the major obstacle of introducing the AIN service, it is shown that most of the interactions are caused by sharing limited resources, and on the basis of this knowledge, an interaction testing and handling logic is designed. Compared with other methods, the FIM has advantages such as a simple process logic, small memory space requirements, and runtime processing, and it is independent of new features. The FIM is designed using Z schema. This paper also shows the testing and handling process of interactions using the set relation of Z schema.

Myeongho Kang

Papers

An Improvement of the Password-Based Authentication Protocol (K1P) on Security against Replay Attacks

An adaptable and reliable authentication protocol for communication networks

Design of service feature interaction manager in AIN

The design and verification of service feature interaction manager on AIN using Z schema