Paper 2013/401
Functional Signatures and Pseudorandom Functions
Elette Boyle and Shafi Goldwasser and Ioana Ivan
Abstract
In this paper, we introduce \emph{functional digital signatures} and \emph{pseudorandom functions}. In a functional signature scheme, in addition to a master signing key that can be used to sign any message, there are \emph{signing keys for a function} $f$, which allow one to sign any message in the range of $f$. We show applications of functional signatures to construct succinct non-interactive arguments and delegation schemes. We give several general constructions for this primitive based on different computational hardness assumptions, and describe the trade-offs between them in terms of the assumptions they require and the size of the signatures. In a functional pseudorandom function, in addition to a master secret key that can be used to evaluate the pseudorandom function $F$ on any point in the domain, there are additional \emph{secret keys for a function} $f$, which allow one to evaluate $F$ on any $y$ for which there exists an $x$ such that $f(x)=y$. This implies the ability to delegate keys per function $f$ for computing a pseudorandom function $F$ on points $y$ for which $f(y)=1$. We define and provide a sample construction of a functional pseudorandom function family for the prefix-fixing function family. }
Metadata
- Available format(s)
- Publication info
- Published elsewhere. Unknown where it was published
- Contact author(s)
- ioanai @ mit edu
- History
- 2013-10-29: last of 3 revisions
- 2013-06-20: received
- See all versions
- Short URL
- https://ia.cr/2013/401
- License
-
CC BY