Template Class BigIntegerInterface

Defined in File integer.h

Page Contents

Template Parameter Order
Class Documentation

Template Parameter Order

typename T

Class Documentation

template<typename T> class lbcrypto::BigIntegerInterface

Public Functions

void SetValue(const std::string &str)

Set from a string

Parameters: str – is the string representation of the value

T Add(const T &b) const

Addition operation.

Parameters: &b – is the value to add.
Returns: result of the addition operation.

T &AddEq(const T &b)

T Sub(const T &b) const

Subtraction operation.

Parameters: &b – is the value to subtract.
Returns: is the result of the subtraction operation.

T &SubEq(const T &b)

T Mul(const T &b) const

Multiplication operation.

Parameters: &b – is the value to multiply with.
Returns: is the result of the multiplication operation.

T &MulEq(const T &b)

Multiplication operation. In-place variant.

Parameters: &b – is the value to multiply with.
Returns: is the result of the multiplication operation.

T DividedBy(const T &b) const

Division operation.

Parameters: &b – is the value to divide by.
Returns: is the result of the division operation.

T &DividedByEq(const T &b)

Division operation. In-place variant.

Parameters: &b – is the value to divide by.
Returns: is the result of the division operation.

T MultiplyAndRound(const T &p, const T &q) const

Multiply and Rounding operation. Returns [x*p/q] where [] is the rounding operation.

Parameters

&p – is the numerator to be multiplied.
&q – is the denominator to be divided.

Returns

is the result of multiply and round operation.

T &MultiplyAndRoundEq(const T &p, const T &q)

T DivideAndRound(const T &q) const

Divide and Rounding operation. Returns [x/q] where [] is the rounding operation.

Parameters: &q – is the denominator to be divided.
Returns: is the result of divide and round operation.

T &DivideAndRoundEq(const T &q)

T Mod(const T &modulus) const

Naive modulus operation.

Parameters: &modulus – is the modulus to perform.
Returns: is the result of the modulus operation.

T &ModEq(const T &modulus)

T ComputeMu() const

Precomputes a parameter mu for Barrett modular reduction.

Returns: the precomputed parameter mu.

T Mod(const T &modulus, const T &mu) const

Barrett modulus operation. Implements generalized Barrett modular reduction algorithm. Uses one precomputed value of mu.

Parameters

&modulus – is the modulus to perform.
&mu – is the Barrett value.

Returns

is the result of the modulus operation.

T &ModEq(const T &modulus, const T &mu)

T ModAdd(const T &b, const T &modulus) const

Modulus addition operation.

Parameters

&b – is the scalar to add.
&modulus – is the modulus to perform operations with.

Returns

is the result of the modulus addition operation.

T &ModAddEq(const T &b, const T &modulus)

T ModAddFast(const T &b, const T &modulus) const

Modulus addition where operands are < modulus.

Parameters

&b – is the scalar to add.
&modulus – is the modulus to perform operations with.

Returns

is the result of the modulus addition operation.

T &ModAddFastEq(const T &b, const T &modulus)

T ModAdd(const T &b, const T &modulus, const T &mu) const

Barrett modulus addition operation.

Parameters

&b – is the scalar to add.
&modulus – is the modulus to perform operations with.
&mu – is the Barrett value.

Returns

is the result of the modulus addition operation.

T &ModAddEq(const T &b, const T &modulus, const T &mu)

T ModSub(const T &b, const T &modulus) const

Modulus subtraction operation.

Parameters

&b – is the scalar to subtract.
&modulus – is the modulus to perform operations with.

Returns

is the result of the modulus subtraction operation.

T &ModSubEq(const T &b, const T &modulus)

T ModSubFast(const T &b, const T &modulus) const

Modulus subtraction where operands are < modulus.

Parameters

&b – is the scalar to subtract.
&modulus – is the modulus to perform operations with.

Returns

is the result of the modulus subtraction operation.

T &ModSubFastEq(const T &b, const T &modulus)

T ModSub(const T &b, const T &modulus, const T &mu) const

Barrett modulus subtraction operation.

Parameters

&b – is the scalar to subtract.
&modulus – is the modulus to perform operations with.
&mu – is the Barrett value.

Returns

is the result of the modulus subtraction operation.

T &ModSubEq(const T &b, const T &modulus, const T &mu)

T ModMul(const T &b, const T &modulus) const

Modulus multiplication operation.

Parameters

&b – is the scalar to multiply.
&modulus – is the modulus to perform operations with.

Returns

is the result of the modulus multiplication operation.

T &ModMulEq(const T &b, const T &modulus)

T ModMul(const T &b, const T &modulus, const T &mu) const

Barrett modulus multiplication.

Parameters

&b – is the scalar to multiply.
&modulus – is the modulus to perform operations with.
&mu – is the Barrett value.

Returns

is the result of the modulus multiplication operation.

T &ModMulEq(const T &b, const T &modulus, const T &mu)

T ModMulFast(const T &b, const T &modulus) const

Modulus multiplication that assumes the operands are < modulus.

Parameters

&b – is the scalar to multiply.
&modulus – is the modulus to perform operations with.

Returns

is the result of the modulus multiplication operation.

T &ModMulFastEq(const T &b, const T &modulus)

T ModMulFast(const T &b, const T &modulus, const T &mu) const

Barrett modulus multiplication that assumes the operands are < modulus.

Parameters

&b – is the scalar to multiply.
&modulus – is the modulus to perform operations with.
&mu – is the Barrett value.

Returns

is the result of the modulus multiplication operation.

T &ModMulFastEq(const T &b, const T &modulus, const T &mu)

T ModMulFastConst(const T &b, const T &modulus, const T &bInv) const

NTL-optimized modular multiplication using a precomputation for the multiplicand. Assumes operands are < modulus.

Parameters

&b – is the scalar to multiply.
&modulus – is the modulus to perform operations with.
&bInv – NTL precomputation for b.

Returns

is the result of the modulus multiplication operation.

T &ModMulFastConstEq(const T &b, const T &modulus, const T &bInv)

T ModExp(const T &b, const T &modulus) const

Modulus exponentiation operation.

Parameters

&b – is the scalar to exponentiate at all locations.
&modulus – is the modulus to perform operations with.

Returns

is the result of the modulus exponentiation operation.

T &ModExpEq(const T &b, const T &modulus)

T ModInverse(const T &modulus) const

Modulus inverse operation.

Parameters: &modulus – is the modulus to perform.
Returns: is the result of the modulus inverse operation.

T &ModInverseEq(const T &modulus)

T LShift(usshort shift) const

Left shift operation.

Parameters: shift – # of bits.
Returns: result of the shift operation.

T &LShiftEq(usshort shift)

T RShift(usshort shift) const

Right shift operation.

Parameters: shift – # of bits.
Returns: result of the shift operation.

T &RShiftEq(usshort shift)

int Compare(const T &a) const

Compares the current BigInteger to BigInteger a.

Parameters: a – is the BigInteger to be compared with.
Returns: -1 for strictly less than, 0 for equal to and 1 for strictly greater than conditons.

uint64_t ConvertToInt() const

Convert the value to an int.

Returns: the int representation of the value.

usint GetMSB() const

Returns the MSB location of the value.

Returns: the index of the most significant bit.

usint GetLengthForBase(usint base) const

Get the number of digits using a specific base - support for arbitrary base may be needed.

Parameters: base – is the base with which to determine length in.
Returns: the length of the representation in a specific base.

usint GetDigitAtIndexForBase(usint index, usint base) const

Get the number of digits using a specific base - support for arbitrary base may be needed. Example: for number 83, index 2 and base 4 we have:

                    index:0,1,2,3

83 —base 4 decomposition–> (3,0,1,1) —at index 2–> 1

The return number is 1.

Parameters

index – is the location to return value from in the specific base.
base – is the base with which to determine length in.

Returns

the length of the representation in a specific base.

const std::string ToString() const

Convert this integer into a std::string, for serialization

Returns: the value of this T as a string.

Protected Functions

~BigIntegerInterface() = default

Friends

inline friend T operator+(const T &a, const T &b): inline operators for the addition operation.

inline friend T &operator+=(T &a, const T &b)

inline friend T operator-(const T &a, const T &b): inline operators for the subtraction operation.

inline friend T &operator-=(T &a, const T &b)

inline friend T operator*(const T &a, const T &b): inline operators for the multiplication operation.

inline friend T &operator*=(T &a, const T &b)

inline friend T operator/(const T &a, const T &b): inline operators for the division operation.

inline friend T &operator/=(T &a, const T &b)

inline friend T operator%(const T &a, const T &b)

inline friend T &operator%=(T &a, const T &b)

inline friend T operator<<(const T &a, usshort shift): inline operators for the left shift operations.

inline friend T &operator<<=(T &a, usshort shift)

inline friend T operator>>(const T &a, usshort shift): inline operators for the right shift operations.

inline friend T &operator>>=(T &a, usshort shift)

inline friend bool operator==(const T &a, const T &b)

inline friend bool operator!=(const T &a, const T &b)

inline friend bool operator>(const T &a, const T &b)

inline friend bool operator>=(const T &a, const T &b)

inline friend bool operator<(const T &a, const T &b)

inline friend bool operator<=(const T &a, const T &b)