Oblivious Transfer via Lossy Encryption from Lattice-Based Cryptography

Algorithm 2

The oblivious transfer functionality .

interacts with a receiver and a sender .

(i) Upon receiving a command from , store the pair for

. (Notably, the length of the string is fixed and all parties know);

(ii) Upon receiving a command from , then check if was

previously sent and send the message to , and send the adversary the

message and halt. Otherwise, send nothing to .