Privacy Notions
WIP
Andreas Pfitzmann (TU Dresden), Marit Hansen (ULD, Kiel)
• Execution correctness. Malicious parties cannot create valid transactions if the death predicate of some consumed record or the birth predicate of some created record is not satisfied.
• Execution privacy. Transactions reveal only the information revealed in the memorandum field, a bound on the number of consumed records, and a bound on the number of created records.6 All other information is hidden, including the payloads and predicates of all involved records. For example, putting aside the information revealed in the memorandum (which is arbitrary), one cannot link a transaction that consumes a record with the prior transaction that created it.
• Consumability. Every record can be consumed at least once and at most once by parties that know its secrets. Thus, a malicious party cannot create two valid records for another party such that only one of them can be consumed. (This captures security against “faerie-gold” attacks HBHW18.) • Transaction non-malleability. Malicious parties cannot modify a transaction “in flight” to the ledger
NDSS'19
Section D. Comparison of Privacy Notions and Guarantees for payment channel networks
Denition 4. Anonymity holds if no PPT A has non-negligible advantage in the anonymity game.