TY - GEN
T1 - Beyond the Csiszár-Korner Bound
T2 - 42nd Annual International Cryptology Conference, CRYPTO 2022
AU - Ishai, Yuval
AU - Korb, Alexis
AU - Lou, Paul
AU - Sahai, Amit
N1 - Publisher Copyright:
© 2022, International Association for Cryptologic Research.
PY - 2022
Y1 - 2022
N2 - A wiretap coding scheme (Wyner, Bell Syst. Tech. J. 1975) enables Alice to reliably communicate a message m to an honest Bob by sending an encoding c over a noisy channel ChB, while at the same time hiding m from Eve who receives c over another noisy channel ChE. Wiretap coding is clearly impossible when ChB is a degraded version of ChE, in the sense that the output of ChB can be simulated using only the output of ChE. A classic work of Csiszár and Korner (IEEE Trans. Inf. Theory, 1978) shows that the converse does not hold. This follows from their full characterization of the channel pairs (ChB, ChE) that enable information-theoretic wiretap coding. In this work, we show that in fact the converse does hold when considering computational security; that is, wiretap coding against a computationally bounded Eve is possible if and only if ChB is not a degraded version of ChE. Our construction assumes the existence of virtual black-box (VBB) obfuscation of specific classes of “evasive” functions that generalize fuzzy point functions, and can be heuristically instantiated using indistinguishability obfuscation. Finally, our solution has the appealing feature of being universal in the sense that Alice’s algorithm depends only on ChB and not on ChE.
AB - A wiretap coding scheme (Wyner, Bell Syst. Tech. J. 1975) enables Alice to reliably communicate a message m to an honest Bob by sending an encoding c over a noisy channel ChB, while at the same time hiding m from Eve who receives c over another noisy channel ChE. Wiretap coding is clearly impossible when ChB is a degraded version of ChE, in the sense that the output of ChB can be simulated using only the output of ChE. A classic work of Csiszár and Korner (IEEE Trans. Inf. Theory, 1978) shows that the converse does not hold. This follows from their full characterization of the channel pairs (ChB, ChE) that enable information-theoretic wiretap coding. In this work, we show that in fact the converse does hold when considering computational security; that is, wiretap coding against a computationally bounded Eve is possible if and only if ChB is not a degraded version of ChE. Our construction assumes the existence of virtual black-box (VBB) obfuscation of specific classes of “evasive” functions that generalize fuzzy point functions, and can be heuristically instantiated using indistinguishability obfuscation. Finally, our solution has the appealing feature of being universal in the sense that Alice’s algorithm depends only on ChB and not on ChE.
UR - http://www.scopus.com/inward/record.url?scp=85141719509&partnerID=8YFLogxK
U2 - 10.1007/978-3-031-15979-4_20
DO - 10.1007/978-3-031-15979-4_20
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AN - SCOPUS:85141719509
SN - 9783031159787
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 573
EP - 602
BT - Advances in Cryptology – CRYPTO 2022 - 42nd Annual International Cryptology Conference, CRYPTO 2022, Proceedings
A2 - Dodis, Yevgeniy
A2 - Shrimpton, Thomas
Y2 - 15 August 2022 through 18 August 2022
ER -