org.bouncycastle.pqc.math.ntru

Class PolynomialModTest

java.lang.Object

junit.framework.Assert

junit.framework.TestCase

org.bouncycastle.pqc.math.ntru.PolynomialModTest

All Implemented Interfaces:

junit.framework.Test

public class PolynomialModTest
extends junit.framework.TestCase

Regression tests for NTRU's modular reductions.

Polynomial.mod3(short), Polynomial.mod3(byte) and Polynomial.modQ(int, int) used to be written with the % operator, which compiles to an integer division whose latency depends on its operands - and all three run on secret data (the secret key polynomials f and g, the message polynomials r and m, and the coefficients recovered during decapsulation). They are now division-free, matching the reference implementation, and these tests pin them to the values % produced across the entire input domain that reaches them.

This test has to live in org.bouncycastle.pqc.math.ntru rather than the ...ntru.test package alongside PolynomialTest, because the methods are package-private.

Constructor Summary

Constructors

Constructor and Description
PolynomialModTest()

Method Summary

Modifier and Type	Method and Description
void	testMod3ByteOverEveryInput()
void	testMod3IsAlwaysTernary() The callers treat the result as a ternary coefficient, so nothing may escape 0..2 - the masked conditional subtraction has to leave the folded value fully reduced.
void	testMod3ShortOverEveryInput()
void	testModQIsInRange()
void	testModQOverEveryInputAndParameterSet() Every call site passes a dividend already masked to 16 bits, so that is the domain that has to agree with %; q is a power of two for every parameter set.

Methods inherited from class junit.framework.TestCase

assertEquals, assertEquals, assertEquals, assertEquals, assertEquals, assertEquals, assertEquals, assertEquals, assertEquals, assertEquals, assertEquals, assertEquals, assertEquals, assertEquals, assertEquals, assertEquals, assertEquals, assertEquals, assertEquals, assertEquals, assertFalse, assertFalse, assertNotNull, assertNotNull, assertNotSame, assertNotSame, assertNull, assertNull, assertSame, assertSame, assertTrue, assertTrue, countTestCases, createResult, fail, fail, failNotEquals, failNotSame, failSame, format, getName, run, run, runBare, runTest, setName, setUp, tearDown, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

PolynomialModTest

public PolynomialModTest()

Method Detail

testMod3ShortOverEveryInput

public void testMod3ShortOverEveryInput()

testMod3ByteOverEveryInput

public void testMod3ByteOverEveryInput()

testMod3IsAlwaysTernary

public void testMod3IsAlwaysTernary()

The callers treat the result as a ternary coefficient, so nothing may escape 0..2 - the masked conditional subtraction has to leave the folded value fully reduced.

testModQOverEveryInputAndParameterSet

public void testModQOverEveryInputAndParameterSet()

Every call site passes a dividend already masked to 16 bits, so that is the domain that has to agree with %; q is a power of two for every parameter set.

testModQIsInRange

public void testModQIsInRange()