Summary: Cryptography with Constant Input Locality #
(extended abstract)
Benny Applebaum, Yuval Ishai ## , and Eyal Kushilevitz # # #
Computer Science Department, Technion, Haifa 32000, Israel
{abenny,yuvali,eyalk}@cs.technion.ac.il
Abstract. We study the following natural question: Which cryptographic
primitives (if any) can be realized by functions with constant input lo­
cality, namely functions in which every bit of the input influences only a
constant number of bits of the output? This continues the study of cryp­
tography in low complexity classes. It was recently shown (Applebaum et
al., FOCS 2004) that, under standard cryptographic assumptions, most
cryptographic primitives can be realized by functions with constant out­
put locality, namely ones in which every bit of the output is influenced
by a constant number of bits from the input.
We (almost) characterize what cryptographic tasks can be performed
with constant input locality. On the negative side, we show that prim­
itives which require some form of non­malleability (such as digital sig­
natures, message authentication, or non­malleable encryption) cannot
be realized with constant input locality. On the positive side, assuming
the intractability of certain problems from the domain of error correcting

Source: Applebaum, Benny - Faculty of Mathematics and Computer Science, Weizmann Institute of Science

Collections: Computer Technologies and Information Sciences