Generating certification authority authenticated public keys in ad hoc networks

Abstract

In an ad hoc network, nodes may face the need to generate new public keys. To be verifiably authentic, these newly generated public keys need to be certified. However, because of the absence of a permanent communication infrastructure, a certification authority (CA) that can issue certificates may not always be reachable. The downside is that secure communication channels cannot be established. Previously proposed solutions do not guarantee that identities contained in certificates are valid or, when they do, they rely on neighbors to validate user-key bindings. However, there is no guarantee that nodes that are known in advance will always be present in the network. Therefore, neighbors are not always able to verify a node's identity before certificate issuance. In this paper we define a scheme that permits nodes to generate, on-demand, and independently of any third entity, public keys that can be authenticated with the aid of a unique certificate, issued by a CA at initialization. This certificate binds a valid identity to a hash code. We then extend this scheme to a solution permitting certificates to be generated, on-demand, and independently of any third entity, that can be authenticated with a unique signature generated by a CA. Finally we solve the problem of updated revocation information.

An Enhanced Security Protocol for VANET-Based Entertainment Services

“…An important element of such systems is preventing either the buyer or seller from repudiating a transaction. Historically, these systems have relied on TA-based [6], [7], [8] and certificatebased [9], [10], [11], [12] methods to ensure nonrepudiation. In the TA-based nonrepudiation protocols, a buyer and a seller allow a TA to store information about the multimedia transactions.…”

“…In this section, we describe two security schemes that solve these two important problems. They are a certificateless signature scheme [13] and Kounga et al's scheme [11], [12].…”

“…In Kounga et al's scheme [11], [12], a user does not have to revoke a public/private key pair before its expiration. This is because attackers do not have enough time to compromise a private key during its short lifetime.…”

Cryptanalysis and Improvement of a Biometric-Based Multi-Server Authentication and Key Agreement Scheme

“…Since the first one was proposed by Lamport, a great number of authentication schemes have been presented, which provide authorized communication between remote entities [ 4 – 9 ]. According to the evidences adopted in the authentication, the existing schemes are divided into two categories: certificate-based and identity-based [ 10 – 16 ]. The former category requires the high computation cost and large storage space for the management of certificate store.…”