In recent years, the rapid development of Quantum Computing technology has had a huge impact on the security of traditional Public Key Cryptography. However, the security of Hash functions and Symmetric Cryptographic algorithms is relatively less impacted by this security threaten and commonly have higher execution efficiency. This two primitives can offset the security impact by appropriately increasing the output scale of a Hash function and symmetric key respectively. Therefore, the Symmetric Key Authenticated Key Agreement(SAKA) protocol which constructed mainly by Hash functions and symmetric cryptographic algorithms has gradually attracted more attention. In this paper we proposed a provably secure SAKA scheme. We extend the security model used by Ferreira et al to formally prove the security of our protocol by introducing a criterion for indistinguishability of identities and Synchronization Robustness property. Our protocol not only captures basic security properties such as Perfect Forward Secrecy, Entity Authentication and Key Indistinguishability but also achieved Privacy Preservation and Full Synchronization Robustness. Furthermore, its implementation does not need to rely on a huge and complex Public key Infrastructure(PKI), so we can easily deploy it in a coucurrent environment. Comparison results indicate that the proposal consumes the least computation resource and reasonable communication cost among nine SAKA protocols while equiping 10 security properties.
In recent years, the rapid development of Quantum Computing technology has had a huge impact on the security of traditional Public Key Cryptography. However, the security of Hash functions and Symmetric Cryptographic algorithms is relatively less impacted by this security threaten and commonly have higher execution efficiency. This two primitives can offset the security impact by appropriately increasing the output scale of a Hash function and symmetric key respectively. Therefore, the Symmetric Key Authenticated Key Agreement(SAKA) protocol which constructed mainly by Hash functions and symmetric cryptographic algorithms has gradually attracted more attention. In this paper we proposed a provably secure SAKA scheme. We extend the security model used by Ferreira et al to formally prove the security of our protocol by introducing a criterion for indistinguishability of identities and Synchronization Robustness property. Our protocol not only captures basic security properties such as Perfect Forward Secrecy, Entity Authentication and Key Indistinguishability but also achieved Privacy Preservation and Full Synchronization Robustness. Furthermore, its implementation does not need to rely on a huge and complex Public key Infrastructure(PKI), so we can easily deploy it in a coucurrent environment. Comparison results indicate that the proposal consumes the least computation resource and reasonable communication cost among nine SAKA protocols while equiping 10 security properties.
The last decade has witnessed a sharp spike in the popularity of group applications, such as multi-media conferencing, collaborative workspaces, as well as dynamic coalitions common in law enforcement and disaster rescue scenarios. Standard security services required in such group settings (such as confidentiality, integrity and authentication) can be efficiently achieved if all group members share a secret key. A group key agreement protocol (GKA) provide a technique for any set of participating players to collaboratively establish a shared key.
In this thesis, we tackle two challenging issues in GKA: robustness and privacy-preserving authentication. Robustness improves performance by guaranteeing completion of GKA protocols despite participating player or communication failures. Affiliation-hiding authenticated GKA prevents from man-in-the-middle-attacks by authenticating players in a privacy-preserving manner.
We propose a two-round group key agreement protocol, which offers a natural trade-off between message size and the desired level of fault-tolerance. We demonstrate that in a realistic setting of random player faults, the new protocol has logarithmic-sized messages and expected round complexity close to two. We generalize a robust group key agreement protocol to support heterogeneous players for a general environment. We prove the security of the proposed protocols under the standard cryptographic assumptions.
We present the formal definition of the affiliation-hiding GKA in a standard PKI model with re-usable certificates. The model includes strong security properties, called perfect forward secrecy (PFS) and linkable affiliation-hiding (LAH)—that an key agreement protocol might provide in the face of player corruptions and session compromises. We construct two variants of optimal-cost AH-AGKA protocols, which satisfy PFS and LAH notions under the standard cryptographic assumptions in the random oracle model. The protocol yields minimal costs: three rounds of interaction matches the round complexity of non-private PFS authenticated GKA and its computation costs are comparable to the cost of unauthenticated GKA.
By far, the extended Canetti-Krawczyk (eCK) model still is one of strongest security model for authenticated key exchange (AKE) protocols. In this paper, a secure authenticated key agreement protocol named SAKA is analyzed in the model, the results show that the SAKA protocol does not support forward security which all key exchange protocol should satisfy. Furthermore, it does not meet security goals of the eCK model. In order to overcome all of above flaws, a variant of SAKA protocol is proposed based on Computation Diffie-Hellman assumption, and secure analysis shows that the new protocol has some good security properties including perfect forward secrecy and known session key excepting those desired security properties that SAKA has. Furthermore, fewer number of modular exponentiation indicates that the new scheme is more efficient.
Anonymity, robust synchronization, and perfect forward secrecy are the most important security properties of authenticated key agreement (AKA) protocols. Designing AKA protocols that simultaneously achieve these security properties and availability in the IoT environment is a challenging task. AKA protocols built using public key cryptographic primitives have advantages in achieving these critical security properties, but performing expensive public-key cryptographic operations is inefficient for resource-constrained IoT devices. The authentication protocols based on symmetric cryptographic primitives are often subject to various attacks. This paper proposes a secure lightweight AKA protocol with critical security properties (called CS-LAKA) for IoT environments without using public-key cryptographic primitives. LAKA cleverly achieves the security goals of anonymity, robust synchronization, and perfect forward secrecy by embedding dynamic identities in authenticators, and a few additional exchange messages are added. This enables LAKA to have both robust security and high efficiency. Subsequently, we perform a formal security analysis to prove that LAKA is secure, and compared with existing related schemes, LAKA has obvious advantages in terms of security, functionality and running performance.
As the fundamental building block for secure communication in the open network, authenticated key agreement protocols are usually constructed in the public key setting. Certificateless public key cryptography combines the advantage of the identity-based public key cryptography (ID-PKC) and the traditional PKI. In this paper, we present a secure and efficient two-party authenticated key agreement protocol based on the efficient certificateless public key encryption scheme due to Cheng and Comley. Security analysis shows that it achieves perfect forward secrecy, PKG forward secrecy and almost all the other known security attributes for authenticated key agreement protocol, such as known-key secrecy, key-compromise impersonation resilience, unknown key-share resilience, known session-specific temporary information security, message independence and no key control. Compared to other comparable schemes, it is more secure and has nice efficiency.
The use of bilinear pairings as a building block for cryptographic protocols, most notably in the construction of identity-based cryptosystems, is a very popular area of cryptographic research. In this thesis, we provide a novel classification of pairing-based group key agreement (GKA) from current literature. We propose a new framework for constructing secure and efficient computationally asymmetric authenticated GKA protocols from identity-based signcryption schemes and adapt this framework to construct a novel identity-based authenticated GKA protocol with perfect forward secrecy. To the best of our knowledge, our protocol is the first that maintains perfect forward secrecy in the presence of auxiliary key agreement protocols. We formally prove the security of our protocols in the random oracle model and show that they are communication and computationally efficient in comparison to the pairing-based protocols from the literature.
Almostall the certificateless two-party authenticated key agreement (CTAKA) protocols found in the literature, suffer either serious security problems or inefficient performance that involves high computational costs.In this paper, we design a secure and efficient CTAKA protocol.Within the proposed CTAKA protocol, the KGC publishes the public keys of the users in a public directory (LDAP server) that has a certificate to prove its identity to the users.The LDAP certificate is the only existing certificate within the scheme.Both the two communicating parties are able to compute a common secret per session key using a secure generated random number.The protocol is fully secure against type 1 attack and fully secure against type 2 attacks under the assumptions that the KGC is an honest party and each party within the network has the full capability to keep its secret values safe.Moreover, the setup of the protocol does not include pairings and the whole key agreement process requires only four point scalar multiplications, two point additions, one hash function evaluation and one message exchange.