Research into a pandemic like Covid-19 needs a tremendous input of patient histories and characteristics. Patients and doctors are only willing to share these sensitive data when they are ensured that the data are solely used by legitimate research laboratories. Asymmetric group key agreement (AGKA) protocols provide a good cryptographic primitive to address this requirement. The AGKA protocols proposed in literature provide users with a common public group key and a different decryption key by relying on compute intensive pairing operations. In this paper, we propose a new primitive, called the Common AGKA (CAGKA) protocol in which the users share the same private-public key pair, resulting in a more efficient solution. By combining Elliptic Curve Qu Vanstone certificates and a recently proposed Canetti–Krawczyk (CK) secure mutual authentication protocol, a one round self-certified pairing free CAGKA protocol is defined, which can be also globally certified after one additional round.

对像 Covid-19 这样的流行病进行研究需要大量输入患者的病史和特征。只有在确保数据仅供合法研究实验室使用时，患者和医生才愿意共享这些敏感数据。非对称组密钥协议 (AGKA) 协议提供了一个很好的加密原语来满足这一要求。文献中提出的 AGKA 协议通过依赖计算密集型配对操作为用户提供了一个公共的公共组密钥和一个不同的解密密钥。在本文中，我们提出了一种新的原语，称为通用 AGKA (CAGKA) 协议，其中用户共享相同的私钥-公钥对，从而产生更有效的解决方案。