Design of Key Exchange Protocol Based on Short Group Signature

Zeyu Yang, Ziqing Wang, Fei Qiu +1 more

Hai Huang, Zhenfu Cao

The well-known method for a group key exchange (GKE) protocol to be against insider attack is to make use of signatures. However, using signatures considerably degrades the performance of the GKE protocol. In this paper, we propose a new method to resist insider attack. The underlying tool of our method is a two-party authenticated key exchange (AKE) protocol, which can be used to authenticate all other participants' session identifiers instead of using signatures. Based on the two- party AKE protocol, we propose an efficient insider-resistant GKE protocol without signatures. We show that our proposal is provably secure against insider attack if the underlying two-party AKE protocol is secure.

José Ignacio Escribano Pablos, María Isabel González Vasco, Misael Enrique Marriaga +1 more

A group authenticated key exchange (GAKE) protocol allows a set of parties belonging to a certain designated group to agree upon a common secret key through an insecure communication network. In the last few years, many new cryptographic tools have been specifically designed to thwart attacks from adversaries which may have access to (different kinds of) quantum computation resources. However, few constructions for group key exchange have been put forward. Here, we propose a four-round GAKE which can be proven secure under widely accepted assumptions in the Quantum Random Oracle Model. Specifically, we integrate several primitives from the so-called Kyber suite of post-quantum tools in a (slightly modified) compiler from Abdalla et al. (TCC 2007). More precisely, taking as a starting point an IND-CPA encryption scheme from the Kyber portfolio, we derive, using results from Hövelmanns et al. (PKC 2020), a two-party key exchange protocol and an IND-CCA encryption scheme and prove them fit as building blocks for our compiled construction. The resulting GAKE protocol is secure under the Module-LWE assumption, and furthermore achieves authentication without the use of (expensive) post-quantum signatures.

Colin Boyd, Wenbo Mao

健二 今本

Fouzia Samiullah, Ming-Lee Gan, Sedat Akleylek +1 more

Quantum computing poses a threat on current cryptography methods, prompting initiatives such as the U.S. National Institute for Standards and Technology (NIST) standardization process toward developing post-quantum cryptographic tools. This process concentrates on deploying “key encapsulation mechanisms” and “signature schemes”, mainly focusing on Group Authenticated key exchange (GAKE), which is crucial for secure group communication while ensuring authentication is immune to quantum attacks. Despite various two-party key exchange designs adaptable for group key exchange protocols with multiple parties, experts face challenges in secure group interactions in a post-quantum environment due to the lack of such group protocols solutions. Addressing the necessity of secure group communication in IoTs, we proposed a GAKE protocol. This paper presents its design and implementation secure under QROM; we compared our initial findings on the “Saber-based GAKE” with a Kyber-based GAKE implementation named “Complied Kyber” proposed by Pablos, focusing on IoTs. Our findings show better efficiency than “Compiled Kyber” regarding overall communication duration, especially when involving up to 2000 participants in group communication. Furthermore, thorough investigation and calculations confirm the Saber-GAKE protocol’s interoperability with IoT contexts. The protocol has worthy computational efficiency, with execution speeds of 0.064 ms on ARM Cortex-M4 and 1.56 ms on ARM Cortex-M0 systems. The memory use is well below the allowed limits, with 50.86 KB on Cortex-M4 and 35.84 KB on Cortex-M0. The performance data validate that the Saber-GAKE protocol can effectively and safely function on IoT devices with limited resources, offering strong protection against quantum computing assaults.