Theory of Cryptography pp 263-280
Characterizing the Cryptographic Properties of Reactive 2-Party Functionalities
- Cite this paper as:
- Jeffs R.A., Rosulek M. (2013) Characterizing the Cryptographic Properties of Reactive 2-Party Functionalities. In: Sahai A. (eds) Theory of Cryptography. Lecture Notes in Computer Science, vol 7785. Springer, Berlin, Heidelberg
In secure multi-party computation, a reactive functionality is one which maintains persistent state, takes inputs, and gives outputs over many rounds of interaction with its parties. Reactive functionalities are fundamental and model many interesting and natural cryptographic tasks; yet their security properties are not nearly as well-understood as in the non-reactive case (known as secure function evaluation).
We present new combinatorial characterizations for 2-party reactive functionalities, which we model as finite automata. We characterize the functionalities that have passive-secure protocols, and those which are complete with respect to passive adversaries. Both characterizations are in the information-theoretic setting.