International Association for Cryptologic Research

International Association
for Cryptologic Research

CryptoDB

Christoph Lucas

Publications

Year
Venue
Title
2013
CRYPTO
2009
EPRINT
Combining Computational and Information-Theoretic Security in Multi-Party Computation
Christoph Lucas Dominik Raub Ueli Maurer
Most protocols for multi-party computation (MPC) are secure either against information-theoretic (IT) or against computationally bounded adversaries. In this work, we bring together the best of both worlds: For any robustness parameter $\rob<\frac{n}{2}$ we obtain one MPC protocol that is simultaneously IT secure with robustness for up to $t\leq\rob$ actively corrupted parties, IT secure with fairness (no robustness) for up to $t<\frac{n}{2}$ and computationally secure with agreement on abort (no fairness) for up to $t<n-\rob$. Our construction is secure in the universal composability (UC) framework, and achieves the bounds of Ishai et al. [CRYPTO'06], Katz [STOC'07], and Cleve [STOC'86] on trade-offs between robustness and privacy, and on fairness. For example, for the special case $\rob=0$ our protocol simultaneously achieves non-robust MPC for up to $t<n$ corrupted parties in the computational setting (like Goldreich et al. [STOC'87]) while providing security with fairness in the IT setting for up to $t<\frac{n}{2}$ corrupted parties (like Rabin and Ben-Or [STOC'89] though without robustness).

Coauthors

Martin Hirt (1)
Ueli Maurer (2)
Dominik Raub (1)