A Self-certified and Sybil-Free Framework for Secure Digital Identity Domain Buildup

Abstract

Abstract. An attacker who can control arbitrarily many user identities can break the security properties of most conceivable systems. This is called a "Sybil attack". We present a solution to this problem that does not require online communication with a trusted third party and that in addition preserves the privacy of honest users. Given an initial so-called Sybil-free identity domain, our proposal can be used for deriving Sybilfree unlinkable pseudonyms associated with other identity domains. The pseudonyms are self-certified and computed by the users themselves from their cryptographic long-term identities.

Non-Interactive Privacy-Preserving Sybil-Free Authentication Scheme in VANETs

“…This is possible either by restricting the issuing of pseudonyms or by providing means to detect multiple pseudonyms belonging to a same vehicle. Restricting the issuing of pseudonyms is the better approach, as it completely avoids the problem of detection, which is present in some Sybil-free pseudonym approaches [3], [20]. The proposal from Khodaei et al [17] falls into this category as it is an interactive protocol: pseudonyms are sent to a trusted third party, which is considered to be always available, so that they can be verified.…”

Privacy in Social Collective Intelligence Systems

“…To prevent profiling based on recommendation reports, a privacy-enhancing reputation system using role pseudonyms is presented in [33]. 5 The proposal is based on self-certified pseudonyms that are valid for a given context or service and it limits users to have at most one pseudonym per service [1,32], which prevents Sybil attacks and white-washing. In addition, pseudonyms issued for different services are cryptographically unlinkable.…”