Recoverable Encryption Through Noised Secret

Encryption key safety is the Achilles’ heel of modern cryptography. Simple backup copies offset the risk of key loss, but increase the danger of disclosure, including at the escrow’s site. Recoverable Encryption (RE) alleviates the dilemma. The backup is specifically encrypted so that recovery by brute force, i.e., without any hint from the key owner, remains possible. We propose RE using a noised secret, RENS in short. To dissuade indelicate attempts, the owner sets up the decryption complexity so that recovery time at the escrow’s facility, a computer or perhaps a cluster, becomes inhibitive. The actual recovery fits the time desired by the requestor, using distributed processing over a large cloud. A 10K-node cloud may suffice to recover the key in ten minutes, for the dissuasive set up of seventy days for a single computer. Large public clouds are now available with acceptable price tags. Their sheer size makes the illegal use unlikely. We show feasibility of RENS schemes possibly of interest to numerous applications.