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Oblivious lookup-tables. (English) Zbl 1436.94099

Summary: Evaluating arbitrary functions on encrypted data is one of the holy grails of cryptography, with Fully Homomorphic Encryption (FHE) being probably the most prominent and powerful example. FHE, in its current state is, however, not efficient enough for practical applications. On the other hand, simple homomorphic and somewhat homomorphic approaches are not powerful enough to support arbitrary computations.
We propose a new approach towards a practicable system for evaluating functions on encrypted data. Our approach allows to chain an arbitrary number of computations, which makes it more powerful than existing efficient schemes. As with basic FHE we do not encrypt or in any way hide the function, that is evaluated on the encrypted data. It is, however, sufficient that the function description is known only to the evaluator. This situation arises in practice for software as a Software as a Service (SaaS)-scenarios, where an evaluator provides a function only known to him and the user wants to protect his data. Another application might be the analysis of sensitive data, such as medical records.
In this paper we restrict ourselves to functions with only one input parameter, which allow arbitrary transformations on encrypted data.

MSC:

94A60 Cryptography
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References:

[1] ARMKNECHT, Shift - type homomorphic encryption and its application to fully homomorphic encryption in Progress in th Internat Conf on Cryptology in Africa eds Ifrance Morocco Springer - Verlag Berlin pp, Cryptology AFRICACRYPT 12 pp 234– (2012)
[2] DAMGÅRD, Towards practical public key systems secure against chosen ciphertext attacks in Advances in ed Lecture Notes in Comput Springer - Verlag Berlin pp, Cryptology CRYPTO Sci pp 576– (1992)
[3] SHELAT, Secure computation from millionaire in Advances in st Internat Conf on the Theory and Appl of Cryptology and Inform eds Auckland New Zealand Lecture Notes in Comp Springer - Verlag Berlin pp, Cryptology ASIACRYPT Security Sci pp 15– (2015)
[4] OTTOY, DE STRYCKER Flexible design of a modular simultaneous exponentiation core for embedded platforms in : Reconfigurable Computing : Architectures Tools and Applications Brisk eds Lecture Notes in Comput Springer - Verlag Berlin pp, Sci pp 7806–
[5] GENTRY, Computing arbitrary functions of encrypted data Commun, ACM pp 97– (2010) · Zbl 1315.94074 · doi:10.1145/1666420.1666444
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