Threshold identity authentication signature: Impersonation prevention in social network services

Abstract

Summary While the social network services (SNS) have dominate the ways that people communicate with each other on the Internet, identity impersonation remains to be a serious issue that needs to be solved due to the anonymity in the cyber network. Currently, the potential solution to the problem relies heavily on the administration from the central server, which requires intensive workload of the identity management. In this article, we propose a threshold identity authentication signature scheme to solve the impersonation problem from the protocol layer rather than software design in the traditional upper level. In our scheme, with the help of some authenticated accounts, trusted relationship can be shared in a group to other unauthenticated accounts, which largely decrease the workload of authenticating all the accounts. Users are given the ability to verify other accounts' identity information by their signatures. Then, we establish three security goals to prevent the malicious adversary to launch the impersonation attack on a group. We claim that our scheme is suitable for the SNS scenario since the procedure of generating a signature to prove the identity requires little computation cost, it is user‐friendly especially on the lightweight devices such as mobile devices and so on.

Preventing SNS Impersonation: A Blockchain-Based Approach

“…That is to say, the results of interactions with smart contract are always immediately confirmed at the next block, which is theoretically the fastest response for a blockchain application. In addition, regarding the time cost of off-chain parts like generating signature shares, Chen already demonstrated that they cost an acceptable time for an individual without blockchain in his paper [2]. Therefore, it is not a concern in this paper.…”

“…Therefore, SNS only needs to authenticate a very small number of users. Apart from that, smart contract also takes the role of the verifier, while in [2] the verification has to be done by users repeatedly. From the evaluation of gas and time costs, our scheme is proved to be acceptable for nowadays SNS applications.…”

“…Defects of TIAS. Chen's TIAS scheme [2] focuses on the situation of identity authentication in SNS network. The concept of group is proposed to grant the right of authentication to publicly trusted SNS users (authenticated users).…”

“…The stored information includes uid, address, group name, group public key (MPK), threshold, signature share, flag where uid is the SNS ID, address is the blockchain address, and f lag indicates the trust level of uid to be trusted or semitrusted. Compared to [2], SNS server no longer maintains a database by itself. The blockchain is adopted as a database and smart contract provides an interface for SNS server.…”

“…To solve the impersonation problem in SNS, Chen et al proposed a Threshold Identity Authentication Signature (TIAS) scheme in 2020 [2]. Instead of relying on SNS company, Chen's scheme enables SNS users to endorse other users in the network by themselves.…”