From Passive to Covert Security at Low Cost
- Cite this paper as:
- Damgård I., Geisler M., Nielsen J.B. (2010) From Passive to Covert Security at Low Cost. In: Micciancio D. (eds) Theory of Cryptography. TCC 2010. Lecture Notes in Computer Science, vol 5978. Springer, Berlin, Heidelberg
Aumann and Lindell defined security against covert attacks, where the adversary is malicious, but is only caught cheating with a certain probability. The idea is that in many real-world cases, a large probability of being caught is sufficient to prevent the adversary from trying to cheat. In this paper, we show how to compile a passively secure protocol for honest majority into one that is secure against covert attacks, again for honest majority and catches cheating with probability 1/4. The cost of the modified protocol is essentially twice that of the original plus an overhead that only depends on the number of inputs.