Title
Fully homomorphic encryption with polylog overhead
Abstract
We show that homomorphic evaluation of (wide enough) arithmetic circuits can be accomplished with only polylogarithmic overhead. Namely, we present a construction of fully homomorphic encryption (FHE) schemes that for security parameter λ can evaluate any width-Ω(λ) circuit with t gates in time t· polylog(λ). To get low overhead, we use the recent batch homomorphic evaluation techniques of Smart-Vercauteren and Brakerski-Gentry-Vaikuntanathan, who showed that homomorphic operations can be applied to "packed" ciphertexts that encrypt vectors of plaintext elements. In this work, we introduce permuting/routing techniques to move plaintext elements across these vectors efficiently. Hence, we are able to implement general arithmetic circuit in a batched fashion without ever needing to "unpack" the plaintext vectors. We also introduce some other optimizations that can speed up homomorphic evaluation in certain cases. For example, we show how to use the Frobenius map to raise plaintext elements to powers of p at the "cost" of a linear operation.
Year
DOI
Venue
2012
10.1007/978-3-642-29011-4_28
Lecture Notes in Computer Science
Keywords
DocType
Volume
plaintext vector,homomorphic encryption,polylog overhead,arithmetic circuit,plaintext element,homomorphic evaluation,recent batch homomorphic evaluation,polylogarithmic overhead,general arithmetic circuit,low overhead,homomorphic operation
Conference
2011
ISSN
Citations 
PageRank 
0302-9743
165
5.92
References 
Authors
17
3
Search Limit
100165
Name
Order
Citations
PageRank
Craig Gentry19520380.03
Shai Halevi27203442.70
Nigel P. Smart32808177.13