Public-Key Encryption in the Bounded-Retrieval Model

Date Added: Oct 2009
Format: PDF

The authors construct the first public-key encryption scheme in the Bounded-Retrieval Model (BRM), providing security against various forms of adversarial "Key leakage" attacks. In this model, the adversary is allowed to learn arbitrary information about the decryption key, subject only to the constraint that the overall amount of "Leakage" is bounded by at most l bits. The goal of the BRM is to design cryptographic schemes that can flexibly tolerate arbitrarily leakage bounds l (few bits or many Gigabytes), by only increasing the size of secret key proportionally, but keeping all the other parameters - including the size of the public key, ciphertext, encryption/decryption time, and the number of secret-key bits accessed during decryption - small and independent of l.