We consider the anonymous mutual authentication problem, which consists of a certificate authority, single or multiple verifiers, many legitimate users (provers) and any arbitrary number of illegitimate users. The legal verifier and a legitimate user must be mutually authenticated to each other using the user’s key, while the identity of the user must stay unrevealed. An attacker (illegitimate prover) as well as an illegal verifier must fail in authentication. A general interactive information theoretic framework in a finite field is proposed, where the normalized total key rate as a metric for reliability is defined. Maximizing this rate has a trade-off with establishing anonymity. The problem is studied in two different scenarios: centralized scenario (one single verifier performs the authentication process) and distributed scenario (authentication is done by N verifiers, distributively). For both scenarios, achievable schemes, which satisfy the completeness, soundness (at both verifier and prover) and anonymity properties, are proposed. Increasing the size of the field, results in the key rate approaching its upper bound.
We consider the anonymous mutual authentication problem, which consists of a certificate authority, single or multiple verifiers, many legitimate users (provers) and any arbitrary number of illegitimate users. The legal verifier and a legitimate user must be mutually authenticated to each other using the user’s key, while the identity of the user must stay unrevealed. An attacker (illegitimate prover) as well as an illegal verifier must fail in authentication. A general interactive information theoretic framework in a finite field is proposed, where the normalized total key rate as a metric for reliability is defined. Maximizing this rate has a trade-off with establishing anonymity. The problem is studied in two different scenarios: centralized scenario (one single verifier performs the authentication process) and distributed scenario (authentication is done by N verifiers, distributively). For both scenarios, achievable schemes, which satisfy the completeness, soundness (at both verifier and prover) and anonymity properties, are proposed. Increasing the size of the field, results in the key rate approaching its upper bound.
In this paper, the private authentication problem is considered that consists of a certificate authority, a verifier (or verifiers), many legitimate users (prover) and arbitrary number of attackers. Each legitimate user wants to be authenticated (using his personal key) by the verifier(s), while simultaneously staying anonymous. However, an attacker must fail to be authenticated. We analyze this problem from an information theoretical perspective. First, we propose a general interactive information-theoretic model. As a metric to measure reliability, we consider the key rate whose rate maximization has a trade-off with establishing privacy. We consider the problem in two different setups: single server and multi-server scenarios. In single server scenario one verifier is considered, which all the provers connected to. In multi-server scenario, n verifiers are assumed, where each verifier is connected to a subset of users. For both scenarios, two regimes are considered: finite size and asymptotic regimes. In single server scenario, for both regimes, we propose schemes that satisfy completeness, soundness and privacy properties. Moreover, we show that our scheme achieves capacity in the asymptotic regime. For finite size regime our scheme achieves capacity for large field size. In multi-server scenario two methods are considered: individual and distributed authentication. In individual authentication, the process of authentication is done by one single verifier. In this case, for both regimes, we propose schemes that satisfy completeness, soundness and privacy properties. In distributed authentication, the process of authentication is done collaboratively by all the verifiers. For this case, when all the provers are connected to all the verifiers, we propose an optimal scheme in finite size regime.
This work presents a new scheme based on a quantum zero-knowledge proof for identity authentication. The novelty of this research is the migration of the classical concept Zero-knowledge into the quantum cryptographic framework that, to the best of our knowledge, has never been explored. This approach allows us to take advantage of the principles of quantum mechanics to build a protocol, which is secure against quantum computer attacks, for authenticating several users having access to the same network node. The protocol has been designed, its security analysed and implemented in modified Quantum Key Distribution devices. Two scenarios have been analysed experimentally, the first being both the prover and the verifier honest players, and the second case being the prover a malicious player, the latter demonstrating a notable increase in the quantum bit error rate that prevents a fraudulent authentication.
Authenticated Key Exchange (AKE) is a cryptographic protocol to share a common session key among multiple parties. Usually, PKI-based AKE schemes are designed to guarantee secrecy of the session key and mutual authentication. However, in practice, there are many cases where mutual authentication is undesirable such as in anonymous networks like Tor and Riffle, or difficult to achieve due to the certificate management at the user level such as the Internet. Goldberg et al. formulated a model of anonymous one-sided AKE which guarantees the anonymity of the client by allowing only the client to authenticate the server, and proposed a concrete scheme. However, existing anonymous one-sided AKE schemes are only known to be secure in the random oracle model. In this paper, we propose generic constructions of anonymous one-sided AKE in the random oracle model and in the standard model, respectively. Our constructions allow us to construct the first post-quantum anonymous one-sided AKE scheme from isogenies in the standard model.
In the problem of anonymous authentication (Boneh et al. CCS 1999), a sender wishes to authenticate a message to a given recipient in a way that preserves anonymity: the recipient does not know the identity of the sender and only is assured that the sender belongs to some authorized set. Although solutions for the problem exist (for example, by using ring signatures, e.g. Naor, Crypto 2002), they provide no security when the anonymity set is a singleton. This work is motivated by the question of whether there is any type of anonymity possible in this scenario. It turns out that we can still protect the identity of all senders (authorized or not) if we shift our concern from preventing the identity information be revealed to the recipient to preventing it could be revealed to an external entity, other than the recipient. We define a natural functionality which provides such guarantees and we denote it by Feaa for externally anonymous authenticated channel. We argue that any realization of Feaa must be deniable in the sense of Dodis et al. TCC 2009. To prove the deniability of similar primitives, previous work defined ad hoc notions of deniability for each task, and then each notion was showed equivalent to realizing the primitive in the Generalized Universal Composability framework (GUC, Canetti et al. TCC 2007). Instead, we put forward the question of whether deniability can be defined independently from any particular task. We answer this question in the affirmative providing a natural extension of the definition of Dodis et al. for arbitrary multiparty protocols. Furthermore, we show that a protocol satisfies this definition if an only if it realizes the ideal functionality Fden in the GUC framework. This result enables us to prove that most GUC functionalities we are aware of (and their realizations) are deniable. We conclude by applying our results to the construction of a deniable protocol that realizes Feaa.
A new interactive quantum zero-knowledge protocol for identity authentication implementable in currently available quantum cryptographic devices is proposed and demonstrated. The protocol design involves a verifier and a prover knowing a pre-shared secret, and the acceptance or rejection of the proof is determined by the quantum bit error rate. It has been implemented in modified Quantum Key Distribution devices executing two fundamental cases. In the first case, all players are honest, while in the second case, one of the users is a malicious player. We demonstrate an increase of the quantum bit error rate around 25% in the latter case compared to the case of honesty. The protocol has also been validated for distances from a back-to-back setup to more than 60 km between verifier and prover. The security and robustness of the protocol has been analysed, demonstrating its completeness, soundness and zero-knowledge properties.
With the rise of the Internet of Things (IoT), maintaining data confidentiality and protecting user privacy have become increasingly challenging. End devices in the IoT are often deployed in unattended environments and connected to open networks, making them vulnerable to physical tampering and other security attacks. Different authentication key agreement (AKA) schemes have been used in practice; several of them do not cover the necessary security features or are incompatible with resource-constrained end devices. Their security proofs have been performed under the Random-Oracle model. We present an AKA protocol for end devices and servers. The proposal leverages the ECC-based key exchange mechanism and one-way hash function-based message authentication method to achieve mutual authentication, user anonymity, and forward security. A formal security proof of the proposed scheme is performed under the standard model and the eCK model with the elliptic curve encryption computational assumptions, and formal verification is performed with ProVerif. According to the performance comparison, it is revealed that the proposed scheme offers user anonymity, perfect forward security, and mutual authentication, and resists typical attacks such as ephemeral secret leakage attacks, impersonation attacks, man-in-the-middle attacks, and key compromise impersonation attacks. Moreover, the proposed scheme has the lowest computational and communication overhead compared to existing schemes.