ChainPass: A Privacy-preserving Complete Cross-chain Authentication for Consortium Blockchains

Consortium blockchains have been widely used in many industries such as medical care, finance, and so on. The business data on different blockchains are isolated from each other. In order to share the value data, it is necessary to achieve cross-chain access. Existing cross-chain technologies are mainly aimed at public blockchains, while consortium blockchain users hold identity credentials to participate in transactions, which has higher security requirements. In addition, most of the existing consortium blockchains use pluggable cryptography components. If all consortium blockchains participating in the cross-chain are required to be configured with the same cryptosystem, the cost will be too high. To solve the above privacy protection and compatibility issues, we propose a privacy-preserving complete cross-chain authentication scheme and name it ChainPass. Chain-Pass introduces paillier homomorphic encryption and pseudonym technologies, allowing users to use the original cryptosystem to generate public and private keys and participate in cross-chain transactions. At the same time, the user's pseudonym is updated according to the user's public key. ChainPass protects users' privacy while ensuring complete compatibility. Security analysis and performance evaluation prove that ChainPass has better security and higher efficiency.