Encoding of an IAPS of groups

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Definition

Let (G,Φ) be an IAPS of groups. In other words, for every n, there is a group Gn, and there is a map Φm,n:Gn×GnGm+n.

An encoding of this IAPS over a binary (or constant-sized) alphabet is the following.

  • For every Gn, we specify an encoding of Gn over that alphabet.
  • For every m,n, we specify an algorithm that takes as input the code for gGm and hGn, and outputs the code for Φm,n(g,h).

Properties

Dense encoding of an IAPS of groups

Further information: dense encoding of an IAPS of groups

An encoding of an IAPS of groups is said to be dense if the maximum possible length of a code-word for Gn is bounded by some constant times the logarithm of the size of Gn.

Polynomial-time encoding of an IAPS of groups

Further information: polynomial-time encoding of an IAPS of groups

An encoding of an IAPS of groups is said to be polynomial-time if:

  • The time taken for all the operations (outputting the identity element, computing the product, computing the inverse, testing for membership) is polynomial in the length of the maximum code-word.
  • The time taken for Φm,n is polynomial in the lengths of the maximum code-words for Gm and Gn.

Examples

Encoding of symmetric groups

Further information: Encoding of symmetric groups

Encoding of genereal linear groups

Further information: Encoding of general linear groups