I am not doubting Sergio's security expertise, but security expertise != theoretical cryptography expertise. Crypto requires providing clear definitions and pro

I am not doubting Sergio's security expertise, but security expertise != theoretical cryptography expertise. Crypto requires providing clear definitions and proofs of security. All I see in the first two links are adhoc constructions, with heuristic arguments for security; no security definitions, no reductions, no proofs. The last link is more formal, and talks about models of computation, but once again does not provide any reductions.