org.cryptimeleon.math.structures.groups.exp

Class Multiexponentiation

java.lang.Object

org.cryptimeleon.math.structures.groups.exp.Multiexponentiation

public class Multiexponentiation
extends java.lang.Object

Mutable object describing a multiexponentiation as constant * product(g_i^x_i).

Constructor Summary

Constructors

Constructor and Description
Multiexponentiation()

Method Summary

Modifier and Type	Method and Description
int	computeMinPrecomputedWindowSize(MultiExpAlgorithm multiExpAlgorithm) Computes the minimum window size currently offered by the precomputations of all terms as required for the given algorithm.
void	ensurePrecomputation(int windowSize, MultiExpAlgorithm multiExpAlgorithm) Ensures that all terms support the given window size by performing the precomputations that are necessary to reach the desired window size for the interleaved sliding window algorithm.
java.util.Optional<GroupElementImpl>	getConstantFactor()
int	getNumberOfTerms()
java.util.List<MultiExpTerm>	getTerms()
boolean	isEmpty()
void	put(GroupElementImpl groupelem)
void	put(GroupElementImpl base, java.math.BigInteger exponent, SmallExponentPrecomputation precomputation)
void	put(MultiExpTerm term)
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Multiexponentiation

public Multiexponentiation()

Method Detail

put

public void put(MultiExpTerm term)

put

public void put(GroupElementImpl base,
                java.math.BigInteger exponent,
                SmallExponentPrecomputation precomputation)

put

public void put(GroupElementImpl groupelem)

ensurePrecomputation

public void ensurePrecomputation(int windowSize,
                                 MultiExpAlgorithm multiExpAlgorithm)

Ensures that all terms support the given window size by performing the precomputations that are necessary to reach the desired window size for the interleaved sliding window algorithm.

Parameters:

windowSize - The window size to ensure support for

computeMinPrecomputedWindowSize

public int computeMinPrecomputedWindowSize(MultiExpAlgorithm multiExpAlgorithm)

Computes the minimum window size currently offered by the precomputations of all terms as required for the given algorithm. This is the window size such that all term's bases have cached precomputations of this size. For the sliding algorithm, we only consider negative powers for negative exponents and positive powers for positive exponents. wNAF may use both interchangeably.

Returns:

The minimum window size supported by all terms.

getTerms

public java.util.List<MultiExpTerm> getTerms()

getNumberOfTerms

public int getNumberOfTerms()

getConstantFactor

public java.util.Optional<GroupElementImpl> getConstantFactor()

isEmpty

public boolean isEmpty()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object