Common use of Usability Clause in Contracts

Usability. The ALPKA 1 scheme cannot be made multiple use, as the proxy requires the knowledge of the combined secret information from solely the sender and the receiver for the re-encryption key. – Transitivity: As this feature involves a property on the proxy re-encryption key, it is only relevant for ALPKA 1. Transitivity is obtained as the re- encryption key combines the secret information of both sender and receiver