Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Cryptography

Dynamic Asymmetric Group Key Agreement Based on SM9 Signature

Guanglu Wei, Tiecheng Bai, Zehua Fan, Gang Wu, Wenxu Chen, peng Qin, Kai Fan

Published Jun 12, 2026• 0 citations
Publisher

Abstract

In 2021, the SM9 identity-based cryptographic algorithm became an ISO/IEC international standard, marking a significant advancement in China’s commercial cryptography technology and international standardization capabilities. The SM9 key exchange protocol, a component of the SM9 algorithm suite, provides secure communication by establishing a shared symmetric key between two parties. However, in a group of n users, directly applying this key exchange protocol requires each user to perform O(n) encryption operations and transmit an O(n)-sized ciphertext to ensure confidentiality, which becomes highly inefficient for large groups. To enable efficient secure group communication, we first develop a batch multi-signature algorithm based on SM9, and then we propose a dynamic asymmetric group key agreement (SMDAGKA) protocol based on this method. Our protocol reduces the required encryption operations and ciphertext size to O(1), significantly improving efficiency. Security proofs demonstrate that our scheme achieves a high level of security, and performance analysis shows that it incurs relatively lower computational overhead than related protocols.

DOI
10.3390/cryptography10030037

Related papers

Asymmetric Group Key Agreement Protocol from Short Signatures

Kunyu Shen, Lei Zhang, Rui Zhang +1 more

Asymmetric group key agreement allows a group of users to negotiate a public encryption key that corresponds to several decryption keys, and each decryption key can only be computed by one group member. This novel notion ensures the confidentiality of communication among group members and allows any external entity to send messages to the group. However, the existing authenticated asymmetric group key agreement protocols are designed in identity-based cryptosystem or certificateless public key cryptosystem, which are not widely deployed. In this paper, we propose an efficient authenticated asymmetric group key agreement protocol. The protocol captures the security of secrecy, known-key security, key-compromise impersonation, unknown key-share and key control while being resistant to active attacks. The security of our protocol is reduced to the k-BDHE problem.

IEEE International Conference on Computer and Communications (ICCC)•Dec 9, 2022•3 citations

Constructing group key agreement protocols using mKEMs

Konstantina Papadopoulou

Over the last few years, researchers have introduced many group key agreement protocols, aiming to construct new efficient schemes in terms of both computation and communication. Group key agreement protocols aim to derive a common session key among a group of users, which will be used later in order to achieve secure communication between them. In this thesis, we provide a complete analysis of the protocols that have already been introduced in the literature from 2010 until now and require only one round. The main goal of this analysis is to evaluate these protocols in both communication and computation cost, in order to provide a comprehensive comparative analysis. The second part of the thesis is to analyze and evaluate the multi key encapsulation mechanisms that exist in the literature. A multi key encapsulation mechanism is the encryption technique by which a symmetric cryptographic algorithm is combined with an asymmetric one. To be more specific, such a mechanism uses an asymmetric cryptographic algorithm, as a method to encrypt the session key, while the key is derived by a symmetric cryptographic algorithm. Finally, we propose two new group key agreement protocols which use the multi key encapsulation mechanisms, and compare them with existing group key agreement protocols. These constructions are based on a generic methodology for creating a group key exchange protocol by using multi key encapsulation mechanisms. For this reason, emphasis has been given to both one round group key agreement protocols and multi key encapsulation mechanisms, in order to examine the possibility of combining them

•Feb 26, 2018•0 citations

AD‐ASGKA – authenticated dynamic protocols for asymmetric group key agreement

Mingchu Li, Xiaodong Xu, Cheng Guo +1 more

Abstract Asymmetric group key agreement is a cryptographic primitive allowing a group of users to negotiate a common public encryption key while each of them holds a different secret private decryption key. Anyone (including outsiders) with the public encryption key can send encrypted messages to the group members, and then the group members can decrypt the messages. Authenticated key agreement protocols authenticate the identities of users to ensure that only the intended group members can establish a session in which the group members can communicate with each other. Dynamic asymmetric group key agreement concerns about the scenarios such as ad hoc networks in which the group members may join or leave at any given time. In this paper, we propose a one‐round authenticated dynamic protocol for symmetric group key agreement. For efficiency reasons, we employ the identity‐based public‐key cryptography (IB‐PKC) to authenticate users rather than the public key infrastructure and the certificate‐less public‐key cryptography. Our analysis shows that the proposals in the paper can resist active attacks and meet many desirable security attributes. Besides, our protocol allows users to join or leave the group at the same time. Furthermore, our protocol is round‐optimal and has a quite good performance as compared with previous works. Copyright © 2016 John Wiley & Sons, Ltd.

Security and Communication Networks•Jan 26, 2016•14 citations

ChatKID: Identity-Based Group Key Distribution Protocol for Instant Messaging

HouZhen WANG, Jiayimei Wang, Wanying Qin +1 more

With the growing demand for instant messaging, securing group chats has become a critical concern. While cryptographic approaches are essential for this purpose, they typically require secure and efficient protocols for either group key agreement or group key distribution. Most existing solutions struggle to achieve efficient key updates and seamless integration with real-world systems. To address these limitations, we We present ChatKID, an identity-based group key distribution protocol. At the architectural level, ChatKID employs an asymmetric design to address the resource imbalance between the group owner and group members in group key distribution. At the technical level, it develops a novel polynomial-based key derivation method that drastically improves key update efficiency, while its compliance with the SM9 cryptographic standard enables easy integration with numerous systems. We provide formal analyses of correctness and security, including resilience against five common attacks (e.g., man-in-the-middle, replay), and achieve forward and backward secrecy. Subsequently, we compare ChatKID with recent protocols and demonstrate its significant advantages in both storage and communication overhead. Notably, for group members—typically resource-constrained mobile devices—ChatKID reduces overhead by one to two orders of magnitude (i.e., to$1/10\sim 1/100$) compared to others. Furthermore, we compare ChatKID with mainstream instant messaging applications and demonstrate advantages in terms of connection dependency, computational overhead, communication overhead, and storage requirements. Finally, simulation experiments indicate its superior performance in typical instant messaging scenarios. Taken together, these results suggest that ChatKID holds significant promise for advancing group key distribution in real-world instant messaging applications.

IEEE Transactions on Dependable and Secure Computing•Dec 29, 2025•1 citation

An authenticated hierarchical asymmetric group key agreement protocol based on identity

Yong Gan, Bingli Wang, Yuan Zhuang +2 more

Asymmetric group key agreement protocol is to negotiate a shared group encryption key. Each member can calculate a decryption key corresponding to the encryption key. With the rapid development of network and system technology, secure information exchange has been one of the foci. In this paper, we propose an authenticated hierarchical asymmetric group key agreement protocol based on identity. Based on the realisation of a round of asymmetric group key agreement, the protocol carries out a second round of agreement. Different levels of secrets exchange information between a group of players with different permissions as the number of rounds increases, which can achieve anonymity and authentication and support dynamic group key updating of nodes to achieve forward and backward security of group key. The protocol proved to be secure under the assumption of bilinear computational Diffie-Hellman problem. The performance analysis shows that the proposed scheme is efficient.

International Journal of Embedded Systems•Jan 1, 2019•1 citation

An authenticated hierarchical asymmetric group key agreement protocol based on identity

Qikun Zhang, Zengyu Cai, Yong Gan +2 more

Asymmetric group key agreement protocol is to negotiate a shared group encryption key. Each member can calculate a decryption key corresponding to the encryption key. With the rapid development of network and system technology, secure information exchange has been one of the foci. In this paper, we propose an authenticated hierarchical asymmetric group key agreement protocol based on identity. Based on the realisation of a round of asymmetric group key agreement, the protocol carries out a second round of agreement. Different levels of secrets exchange information between a group of players with different permissions as the number of rounds increases, which can achieve anonymity and authentication and support dynamic group key updating of nodes to achieve forward and backward security of group key. The protocol proved to be secure under the assumption of bilinear computational Diffie-Hellman problem. The performance analysis shows that the proposed scheme is efficient.

International Journal of Embedded Systems•Jan 1, 2019•0 citations
In 2021, the SM9 identity-based cryptographic algorithm became an ISO/IEC international standard, marking a significant advancement in China’s commercial cryptography technology and international standardization capabilities. The SM9 key exchange protocol, a component of the SM9 algorithm suite, provides secure communication by establishing a shared symmetric key between two parties. However, in a group of n users, directly applying this key exchange protocol requires each user to perform O(n) encryption operations and transmit an O(n)-sized ciphertext to ensure confidentiality, which becomes highly inefficient for large groups. To enable efficient secure group communication, we first develop a batch multi-signature algorithm based on SM9, and then we propose a dynamic asymmetric group key agreement (SMDAGKA) protocol based on this method. Our protocol reduces the required encryption operations and ciphertext size to O(1), significantly improving efficiency. Security proofs demonstrate that our scheme achieves a high level of security, and performance analysis shows that it incurs relatively lower computational overhead than related protocols.
Asymmetric group key agreement allows a group of users to negotiate a public encryption key that corresponds to several decryption keys, and each decryption key can only be computed by one group member. This novel notion ensures the confidentiality of communication among group members and allows any external entity to send messages to the group. However, the existing authenticated asymmetric group key agreement protocols are designed in identity-based cryptosystem or certificateless public key cryptosystem, which are not widely deployed. In this paper, we propose an efficient authenticated asymmetric group key agreement protocol. The protocol captures the security of secrecy, known-key security, key-compromise impersonation, unknown key-share and key control while being resistant to active attacks. The security of our protocol is reduced to the k-BDHE problem.
Over the last few years, researchers have introduced many group key agreement protocols, aiming to construct new efficient schemes in terms of both computation and communication. Group key agreement protocols aim to derive a common session key among a group of users, which will be used later in order to achieve secure communication between them. In this thesis, we provide a complete analysis of the protocols that have already been introduced in the literature from 2010 until now and require only one round. The main goal of this analysis is to evaluate these protocols in both communication and computation cost, in order to provide a comprehensive comparative analysis. The second part of the thesis is to analyze and evaluate the multi key encapsulation mechanisms that exist in the literature. A multi key encapsulation mechanism is the encryption technique by which a symmetric cryptographic algorithm is combined with an asymmetric one. To be more specific, such a mechanism uses an asymmetric cryptographic algorithm, as a method to encrypt the session key, while the key is derived by a symmetric cryptographic algorithm. Finally, we propose two new group key agreement protocols which use the multi key encapsulation mechanisms, and compare them with existing group key agreement protocols. These constructions are based on a generic methodology for creating a group key exchange protocol by using multi key encapsulation mechanisms. For this reason, emphasis has been given to both one round group key agreement protocols and multi key encapsulation mechanisms, in order to examine the possibility of combining them
Abstract Asymmetric group key agreement is a cryptographic primitive allowing a group of users to negotiate a common public encryption key while each of them holds a different secret private decryption key. Anyone (including outsiders) with the public encryption key can send encrypted messages to the group members, and then the group members can decrypt the messages. Authenticated key agreement protocols authenticate the identities of users to ensure that only the intended group members can establish a session in which the group members can communicate with each other. Dynamic asymmetric group key agreement concerns about the scenarios such as ad hoc networks in which the group members may join or leave at any given time. In this paper, we propose a one‐round authenticated dynamic protocol for symmetric group key agreement. For efficiency reasons, we employ the identity‐based public‐key cryptography (IB‐PKC) to authenticate users rather than the public key infrastructure and the certificate‐less public‐key cryptography. Our analysis shows that the proposals in the paper can resist active attacks and meet many desirable security attributes. Besides, our protocol allows users to join or leave the group at the same time. Furthermore, our protocol is round‐optimal and has a quite good performance as compared with previous works. Copyright © 2016 John Wiley & Sons, Ltd.
With the growing demand for instant messaging, securing group chats has become a critical concern. While cryptographic approaches are essential for this purpose, they typically require secure and efficient protocols for either group key agreement or group key distribution. Most existing solutions struggle to achieve efficient key updates and seamless integration with real-world systems. To address these limitations, we We present ChatKID, an identity-based group key distribution protocol. At the architectural level, ChatKID employs an asymmetric design to address the resource imbalance between the group owner and group members in group key distribution. At the technical level, it develops a novel polynomial-based key derivation method that drastically improves key update efficiency, while its compliance with the SM9 cryptographic standard enables easy integration with numerous systems. We provide formal analyses of correctness and security, including resilience against five common attacks (e.g., man-in-the-middle, replay), and achieve forward and backward secrecy. Subsequently, we compare ChatKID with recent protocols and demonstrate its significant advantages in both storage and communication overhead. Notably, for group members—typically resource-constrained mobile devices—ChatKID reduces overhead by one to two orders of magnitude (i.e., to1/10∼1/1001/10\sim 1/1001/10∼1/100) compared to others. Furthermore, we compare ChatKID with mainstream instant messaging applications and demonstrate advantages in terms of connection dependency, computational overhead, communication overhead, and storage requirements. Finally, simulation experiments indicate its superior performance in typical instant messaging scenarios. Taken together, these results suggest that ChatKID holds significant promise for advancing group key distribution in real-world instant messaging applications.
Asymmetric group key agreement protocol is to negotiate a shared group encryption key. Each member can calculate a decryption key corresponding to the encryption key. With the rapid development of network and system technology, secure information exchange has been one of the foci. In this paper, we propose an authenticated hierarchical asymmetric group key agreement protocol based on identity. Based on the realisation of a round of asymmetric group key agreement, the protocol carries out a second round of agreement. Different levels of secrets exchange information between a group of players with different permissions as the number of rounds increases, which can achieve anonymity and authentication and support dynamic group key updating of nodes to achieve forward and backward security of group key. The protocol proved to be secure under the assumption of bilinear computational Diffie-Hellman problem. The performance analysis shows that the proposed scheme is efficient.
Asymmetric group key agreement protocol is to negotiate a shared group encryption key. Each member can calculate a decryption key corresponding to the encryption key. With the rapid development of network and system technology, secure information exchange has been one of the foci. In this paper, we propose an authenticated hierarchical asymmetric group key agreement protocol based on identity. Based on the realisation of a round of asymmetric group key agreement, the protocol carries out a second round of agreement. Different levels of secrets exchange information between a group of players with different permissions as the number of rounds increases, which can achieve anonymity and authentication and support dynamic group key updating of nodes to achieve forward and backward security of group key. The protocol proved to be secure under the assumption of bilinear computational Diffie-Hellman problem. The performance analysis shows that the proposed scheme is efficient.