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A generalization of Burmester-Desmedt GKE based on a non-abelian finite group action

Daniel Camazón Portela, Álvaro Otero Sánchez, Juan Antonio López Ramos

TL;DR

The paper addresses secure group key exchange for dynamic, multi-user groups in a post-quantum setting. It generalizes the Burmester–Desmedt BD protocol to non-abelian finite group actions, presenting a multi-round GKE scheme and a formal security model. The authors prove forward secrecy under a DDH-like group-action assumption and discuss reductions via distribution indistinguishability, while proposing hard-group-action constructions as practical platforms. This work provides a PQ-secure GKE alternative for multicast-style scenarios and broadens the application of non-abelian group actions in cryptographic protocols.

Abstract

The advent of large-scale quantum computers implies that our existing public-key cryptography infrastructure has become insecure. That means that the privacy of many mobile applications involving dynamic peer groups, such as multicast messaging or pay-per-view, could be compromised. In this work we propose a generalization of the well known group key exchange protocol proposed by Burmester and Desmedt to the non-abelian case by the use of finite group actions and we prove that the presented protocol is secure in Katz and Yung's model.

A generalization of Burmester-Desmedt GKE based on a non-abelian finite group action

TL;DR

The paper addresses secure group key exchange for dynamic, multi-user groups in a post-quantum setting. It generalizes the Burmester–Desmedt BD protocol to non-abelian finite group actions, presenting a multi-round GKE scheme and a formal security model. The authors prove forward secrecy under a DDH-like group-action assumption and discuss reductions via distribution indistinguishability, while proposing hard-group-action constructions as practical platforms. This work provides a PQ-secure GKE alternative for multicast-style scenarios and broadens the application of non-abelian group actions in cryptographic protocols.

Abstract

The advent of large-scale quantum computers implies that our existing public-key cryptography infrastructure has become insecure. That means that the privacy of many mobile applications involving dynamic peer groups, such as multicast messaging or pay-per-view, could be compromised. In this work we propose a generalization of the well known group key exchange protocol proposed by Burmester and Desmedt to the non-abelian case by the use of finite group actions and we prove that the presented protocol is secure in Katz and Yung's model.

Paper Structure

This paper contains 7 sections, 3 theorems, 35 equations.

Key Result

Lemma 2.1

Kerber99 The mapping $H(x)\rightarrow H/H_{x}: \phi(h,x)\rightarrow hH_{x}$ is a bijection between the orbit $H(x)$ of $x$ and the set of left cosets $H/H_{x}$.

Theorems & Definitions (24)

  • Definition 1
  • Definition 2
  • Lemma 2.1
  • Definition 3: Double group action
  • Example 1
  • Remark 1
  • Example 2: Commutative case
  • Definition 4
  • Definition 5
  • Proposition 5.1
  • ...and 14 more