ds.ov2.test
Class Exponent_perf_card

java.lang.Object
  ds.ov2.test.Exponent_perf_card

public class Exponent_perf_card
extends Object

Methods for the vector_exp protocol.

CPP Preprocessing

This class uses the following cpp defines: PACKAGE, PUBLIC, ASSERT,

Execution Environment:

card

Author:

Hendrik Tews

Version:

$Revision: 1.12 $

Last Commit:

$Date: 2009-05-25 07:51:19 $ by $Author: tews $

Field Summary

Bignat	result The result.
private RSA_exponent	rsa_exponent The cipher used for exponentiations.
private RSA_exponent	square_exponent The cipher for the squarings if squared multiplication is used.
private Bignat	temp_1 First temporary.
private Bignat	temp_2 Second temporary.
private Bignat	temp_3 Third temporary.

Constructor Summary

Exponent_perf_card(Bignats bignats)
Constructor.

Method Summary

void	vector_exp_init(Modulus modulus, short variant, boolean keep_modulus) Initialization method of the vector_exp_init step.
void	vector_exp(Vector base, Vector exponent, Modulus modulus, short base_factor_size, Vector base_factors, Bignat one_or_correction, short variant, boolean doit) Computation method for the vector_exp_1 and vector_exp_2 steps.

Methods inherited from class java.lang.Object

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

Field Detail

rsa_exponent

private final RSA_exponent rsa_exponent

The cipher used for exponentiations. Alias of Bignats.rsa_exponent.

square_exponent

private final RSA_exponent square_exponent

The cipher for the squarings if squared multiplication is used. Alias of Bignats.square_exp.

result

public final Bignat result

The result. Alias of Bignats.r_1. Must contain the same reference as Exponent_perf_description.result.

temp_1

private final Bignat temp_1

First temporary. Alias of Bignats.r_2.

temp_2

private final Bignat temp_2

Second temporary. Alias of Bignats.r_3.

temp_3

private final Bignat temp_3

Third temporary. Alias of Bignats.r_4.

Constructor Detail

Exponent_perf_card

public Exponent_perf_card(Bignats bignats)

Constructor. Initializes all the aliases to bignats.

Parameters:

bignats - data allocation instance

Method Detail

vector_exp_init

public void vector_exp_init(Modulus modulus,
                            short variant,
                            boolean keep_modulus)

Initialization method of the vector_exp_init step. For the init step the protocol layer transfers all the data (most importantly bases, exponents, modulus and base factors) to the applet. This method initializes the ciphers to be used for exponentiation (if any).

Parameters:

modulus - modulus

variant - multi-power implementation to use

keep_modulus - true if the modulus is the same as in the last test and it therefore should not be installed again; false to reinstall the modulus in all the ciphers.

vector_exp

public void vector_exp(Vector base,
                       Vector exponent,
                       Modulus modulus,
                       short base_factor_size,
                       Vector base_factors,
                       Bignat one_or_correction,
                       short variant,
                       boolean doit)

Computation method for the vector_exp_1 and vector_exp_2 steps. Performs the computation if doit is true. Stores the moduluar multi-power bases[0]^exponent[0] * bases[1]^exponent[1] ... mod modulus in result.

Parameters:

base - the bases

exponent - the exponents

modulus - modulus

base_factor_size - number of bases for which base_factors contains precomputed products (only relevant for the PURE_JAVA variant)

base_factors - the precomputed products of the bases

one_or_correction - a montgomerized one or a suitable Montgomery correction factor

variant - the implementation variant to use, 0 for Exponent_perf_host.Vector_exponent_variant.PURE_JAVA, 1 for Exponent_perf_host.Vector_exponent_variant.MONT_RSA, 2 for Exponent_perf_host.Vector_exponent_variant.SQUARED_RSA

doit - if false skip to call to the multi-power method to measure the transmission overhead