pseudonymsets

A pseudonym set is a cryptographic technique used to allow a single private key to control multiple public keys. This enables a user to maintain anonymity while having a variable number of pseudonyms, where each pseudonym is associated with a unique public key. The core idea is that an observer cannot definitively link transactions or messages sent from different pseudonyms within the same set to the same underlying entity.

The creation of a pseudonym set typically involves a generative process where a single master private key is used to derive multiple individual private keys, each corresponding to a distinct pseudonym. Similarly, a master public key can be used to derive the public keys for each pseudonym. This relationship is crucial for the functioning of the pseudonym set.

When a user wishes to send a message or perform a transaction using a pseudonym from their set, they sign it with the corresponding private key of that pseudonym. However, a key feature is that the signature also incorporates information that proves the public key belongs to *some* pseudonym within the established set, without revealing which specific pseudonym was used. This prevents a verifier from distinguishing between transactions made by different pseudonyms within the same set.

Pseudonym sets are employed in various privacy-enhancing technologies, particularly in the realm of digital currencies and secure communication systems. Their purpose is to enhance user privacy by obfuscating the link between different identities controlled by the same entity, making it harder to track or deanonymize individuals across multiple interactions. The security and effectiveness of pseudonym sets rely on the underlying cryptographic primitives used for key generation and signature schemes.