We advocate schemes based on fixed-key AES as the best route to highly efficient circuit-garbling. We provide such schemes making only one AES call per garbled-gate evaluation. On the theoretical side, we justify the security of these methods in the random-permutation model, where parties have access to a public random permutation. On the practical side, we provide the Just Garble system, which implements our schemes. Just Garble evaluates moderate-sized garbled-circuits at an amortized cost of 23.2 cycles per gate (7.25 nsec), far faster than any prior reported results.

In response to needs of disk encryption standardization bodies, we provide the first tweakable ciphers that are proven to securely encipher their own keys. We provide both a narrowblock design StE and a wideblock design EtE. Our proofs assume only standard PRP-CCA security of the underlying tweakable ciphers.