A class used to encode, encrypt, decode and decrypt ciphertexts and plaintexts. More...

#include <Encoder.h>

Public Member Functions
	Encoder (HeContext &he)
	Constructs a ready to use object. More...

	Encoder (const Encoder &src)=delete
	Copy constructor deleted. Construct new objects when needed.

Encoder &	operator= (const Encoder &src)=delete
	Assignment deleted. Construct new objects when needed.

void	setDefaultScale (double scale)
	Default scale is a parameter relevant to CKKS-like schemes. More...

double	getDefaultScale () const
	Returns the scale used by the encoder as set by setDefaultScale. More...

void	restoreDefaultScale ()
	Restores the default scale to the default scale defined by the HeContext object.

void	setDecryptAddedNoiseEnabled (bool val)
	Allows to determine whether to enable the decrypt added noise. More...

bool	getDecryptAddedNoiseEnabled () const
	Returns a boolean indicating whether to enable the decrypt added noise.

void	setDecryptAddedNoisePrecision (int val)
	Allows to set the level of precision to be preserved in the process of adding decrypt noise, if the decrypt added noise is enabled. More...

int	getDecryptAddedNoisePrecision () const
	Returns an integer indicating precision to be preserved. More...

void	encode (PTile &res, int val, int chainIndex=-1) const
	Encodes the given int into all slots of a PTile. More...

void	encode (PTile &res, double val, int chainIndex=-1) const
	Encodes the given double into all slots of a PTile. More...

void	encode (PTile &res, const std::vector< int > &vals, int chainIndex=-1) const
	Encodes the given vector of integers into a PTile. More...

void	encode (PTile &res, const std::vector< long > &vals, int chainIndex=-1) const
	Encodes the given vector of longs into a PTile. More...

void	encode (PTile &res, const std::vector< double > &vals, int chainIndex=-1) const
	Encodes the given vector of doubles into a PTile. More...

void	encode (PTile &res, const std::vector< std::complex< double >> &vals, int chainIndex=-1) const
	Encodes the given vector of complex numbers into a PTile. More...

std::vector< int >	decodeInt (const PTile &src) const
	Decodes the value of the given PTile into a vector of ints. More...

std::vector< long >	decodeLong (const PTile &src) const
	Decodes the value of the given PTile into a vector of longs. More...

std::vector< double >	decodeDouble (const PTile &src) const
	Decodes the value of the given PTile into a vector of doubles. More...

std::vector< std::complex< double > >	decodeComplex (const PTile &src) const
	Decodes the value of the given PTile into a vector of complex<double>. More...

void	encrypt (CTile &res, const PTile &src) const
	Encrypts "src" into "res". More...

void	decrypt (PTile &res, const CTile &src) const
	Encrypts "src" into "res". More...

void	encodeEncrypt (CTile &res, const std::vector< int > &vals, int chainIndex=-1) const
	Encodes and then encrypts the given vector into a CTile. More...

void	encodeEncrypt (CTile &res, const std::vector< long > &vals, int chainIndex=-1) const
	Encodes and then encrypts the given vector into a CTile. More...

void	encodeEncrypt (CTile &res, const std::vector< double > &vals, int chainIndex=-1) const
	Encodes and then encrypts the given vector into a CTile. More...

void	encodeEncrypt (CTile &res, const std::vector< std::complex< double >> &vals, int chainIndex=-1) const
	Encodes and then encrypts the given vector into a CTile. More...

std::vector< int >	decryptDecodeInt (const CTile &src) const
	Decodes and then decryots the given CTile into a vector of ints. More...

std::vector< long >	decryptDecodeLong (const CTile &src) const
	Decodes and then decryots the given CTile into a vector of ints. More...

std::vector< double >	decryptDecodeDouble (const CTile &src) const
	Decodes and then decryots the given CTile into a vector of doubles. More...

std::vector< std::complex< double > >	decryptDecodeComplex (const CTile &src) const
	Decodes and then decryots the given CTile into a vector of complex<double>. More...

void	printErrorStats (CTile &actualC, std::vector< double > expectedZ, std::ostream &out=std::cout, bool asCsv=false) const
	Prints statstical information relating to the difference between "actualC" and "expectedZ". More...

int	validateChainIndex (int chainIndex) const
	checks whether a chain index is valid. More...

double	assertEquals (const CTile &c, const std::string &title, const std::vector< int > &expectedVals, double eps=1e-6, bool percent=false) const
	Asserts that "c" and "expectedVals" are considered equal. More...

double	assertEquals (const CTile &c, const std::string &title, const std::vector< long > &expectedVals, double eps=1e-6, bool percent=false) const
	Asserts that "c" and "expectedVals" are considered equal. More...

double	assertEquals (const CTile &c, const std::string &title, const std::vector< double > &expectedVals, double eps=1e-6, bool percent=false) const
	Asserts that "c" and "expectedVals" are considered equal. More...

double	assertEquals (const CTile &c, const std::string &title, const std::vector< std::complex< double >> &expectedVals, double eps=1e-6, bool percent=false) const
	Asserts that "c" and "expectedVals" are considered equal. More...

const AbstractEncoder &	getImpl () const
	Reserved for debugging and internal use.

template<typename T >
vector< T >	verifyEncodeVecSize (const vector< T > &vec) const

Detailed Description

A class used to encode, encrypt, decode and decrypt ciphertexts and plaintexts.

Constructor & Destructor Documentation

◆ Encoder()

helayers::Encoder::Encoder ( HeContext & he )

Constructs a ready to use object.

Parameters

[in] he the underlying context.

Member Function Documentation

◆ assertEquals() [1/4]

double helayers::Encoder::assertEquals	(	const CTile &	c,
		const std::string &	title,
		const std::vector< double > &	expectedVals,
		double	eps = `1e-6`,
		bool	percent = `false`
	)		const

Asserts that "c" and "expectedVals" are considered equal.

"c" and "expectedVals" will be considered equal if when decrypting and decoding "c" into a vector, v, one of the following holds:

percent == false and fabs(v[i] - expectedVals[i]) < eps, foreach i.

percent == true and fabs(v[i] - expectedVals[i]) / fabs(v[i]) < eps, foreach i. The maximum found absolute or relative difference (depending on the value of "percent" flag) is returned.

Parameters

[in]	c	The CTile to compare with expectedVals
[in]	title	The title used in case of printing a failure message.
[in]	expectedVals	The vector to compare with "c".
[in]	eps	Comparison tolerance
	]in]	percent If true, the relative difference between "c" and "expectedVals" is checked. Otherwise, the absolute difference is checked.

◆ assertEquals() [2/4]

double helayers::Encoder::assertEquals	(	const CTile &	c,
		const std::string &	title,
		const std::vector< int > &	expectedVals,
		double	eps = `1e-6`,
		bool	percent = `false`
	)		const

Asserts that "c" and "expectedVals" are considered equal.

"c" and "expectedVals" will be considered equal if when decrypting and decoding "c" into a vector, v, one of the following holds:

percent == false and fabs(v[i] - expectedVals[i]) < eps, foreach i.

percent == true and fabs(v[i] - expectedVals[i]) / fabs(v[i]) < eps, foreach i. The maximum found absolute or relative difference (depending on the value of "percent" flag) is returned.

Parameters

[in]	c	The CTile to compare with expectedVals
[in]	title	The title used in case of printing a failure message.
[in]	expectedVals	The vector to compare with "c".
[in]	eps	Comparison tolerance
	]in]	percent If true, the relative difference between "c" and "expectedVals" is checked. Otherwise, the absolute difference is checked.

◆ assertEquals() [3/4]

double helayers::Encoder::assertEquals	(	const CTile &	c,
		const std::string &	title,
		const std::vector< long > &	expectedVals,
		double	eps = `1e-6`,
		bool	percent = `false`
	)		const

Asserts that "c" and "expectedVals" are considered equal.

"c" and "expectedVals" will be considered equal if when decrypting and decoding "c" into a vector, v, one of the following holds:

percent == false and fabs(v[i] - expectedVals[i]) < eps, foreach i.

percent == true and fabs(v[i] - expectedVals[i]) / fabs(v[i]) < eps, foreach i. The maximum found absolute or relative difference (depending on the value of "percent" flag) is returned.

Parameters

[in]	c	The CTile to compare with expectedVals
[in]	title	The title used in case of printing a failure message.
[in]	expectedVals	The vector to compare with "c".
[in]	eps	Comparison tolerance
	]in]	percent If true, the relative difference between "c" and "expectedVals" is checked. Otherwise, the absolute difference is checked.

◆ assertEquals() [4/4]

double helayers::Encoder::assertEquals	(	const CTile &	c,
		const std::string &	title,
		const std::vector< std::complex< double >> &	expectedVals,
		double	eps = `1e-6`,
		bool	percent = `false`
	)		const

Asserts that "c" and "expectedVals" are considered equal.

"c" and "expectedVals" will be considered equal if when decrypting and decoding "c" into a vector, v, one of the following holds:

percent == false and fabs(v[i] - expectedVals[i]) < eps, foreach i.

percent == true and fabs(v[i] - expectedVals[i]) / fabs(v[i]) < eps, foreach i. The maximum found absolute or relative difference (depending on the value of "percent" flag) is returned.

Parameters

[in]	c	The CTile to compare with expectedVals
[in]	title	The title used in case of printing a failure message.
[in]	expectedVals	The vector to compare with "c".
[in]	eps	Comparison tolerance
	]in]	percent If true, the relative difference between "c" and "expectedVals" is checked. Otherwise, the absolute difference is checked.

◆ decodeComplex()

vector< complex< double > > helayers::Encoder::decodeComplex ( const PTile & src ) const

Decodes the value of the given PTile into a vector of complex<double>.

Parameters

[in] src The PTile to decode.

◆ decodeDouble()

vector< double > helayers::Encoder::decodeDouble ( const PTile & src ) const

Decodes the value of the given PTile into a vector of doubles.

Parameters

[in] src The PTile to decode.

◆ decodeInt()

vector< int > helayers::Encoder::decodeInt ( const PTile & src ) const

Decodes the value of the given PTile into a vector of ints.

If the underlying FHE scheme is a scheme that supports floating point values, then "src" is first decrypted into a vector of doubles and then rounded to the nearest integers.

Parameters

[in] src The PTile to decode.

◆ decodeLong()

vector< long > helayers::Encoder::decodeLong ( const PTile & src ) const

Decodes the value of the given PTile into a vector of longs.

If the underlying FHE scheme is a scheme that supports floating point values, then "src" is first decrypted into a vector of doubles and then rounded to the nearest integers.

Parameters

[in] src The PTile to decode.

◆ decrypt()

void helayers::Encoder::decrypt	(	PTile &	res,
		const CTile &	src
	)		const

Encrypts "src" into "res".

Parameters

[out]	res	The resulting PTile.
[in]	src	The CTile to encrypt

◆ decryptDecodeComplex()

vector< complex< double > > helayers::Encoder::decryptDecodeComplex ( const CTile & src ) const

Decodes and then decryots the given CTile into a vector of complex<double>.

Parameters

[in] src The CTile to decode and decrypt.

◆ decryptDecodeDouble()

vector< double > helayers::Encoder::decryptDecodeDouble ( const CTile & src ) const

Decodes and then decryots the given CTile into a vector of doubles.

Parameters

[in] src The CTile to decode and decrypt.

◆ decryptDecodeInt()

vector< int > helayers::Encoder::decryptDecodeInt ( const CTile & src ) const

Decodes and then decryots the given CTile into a vector of ints.

If the underlying FHE scheme is a scheme that supports floating point values, then "src" is first decrypted into a vector of doubles and then rounded to the nearest integers.

Parameters

[in] src The CTile to decode and decrypt.

◆ decryptDecodeLong()

vector< long > helayers::Encoder::decryptDecodeLong ( const CTile & src ) const

Decodes and then decryots the given CTile into a vector of ints.

If the underlying FHE scheme is a scheme that supports floating point values, then "src" is first decrypted into a vector of doubles and then rounded to the nearest integers.

Parameters

[in] src The CTile to decode and decrypt.

◆ encode() [1/6]

void helayers::Encoder::encode	(	PTile &	res,
		const std::vector< double > &	vals,
		int	chainIndex = `-1`
	)		const

Encodes the given vector of doubles into a PTile.

If the size of the given vector is less than slot count, the empty slots of the PTile will be set to zero. If the size of the given vector is more than slot count, a untime_error will be thrown.

Parameters

[out]	res	The encoded PTile
[in]	vals	The vector to encode
[in]	chainIndex	If HeContext is a CKKS context, specifies the chainIndex of the resulting PTile. otherwise, this parameter is ignored.

Exceptions

runtime_error if vals.size() > slot count

◆ encode() [2/6]

void helayers::Encoder::encode	(	PTile &	res,
		const std::vector< int > &	vals,
		int	chainIndex = `-1`
	)		const

Encodes the given vector of integers into a PTile.

If the size of the given vector is less than slot count, the empty slots of the PTile will be set to zero. If the size of the given vector is more than slot count, a untime_error will be thrown.

Parameters

[out]	res	The encoded PTile
[in]	vals	The vector to encode
[in]	chainIndex	If HeContext is a CKKS context, specifies the chainIndex of the resulting PTile. otherwise, this parameter is ignored.

Exceptions

runtime_error if vals.size() > slot count

◆ encode() [3/6]

void helayers::Encoder::encode	(	PTile &	res,
		const std::vector< long > &	vals,
		int	chainIndex = `-1`
	)		const

Encodes the given vector of longs into a PTile.

If the size of the given vector is less than slot count, the empty slots of the PTile will be set to zero. If the size of the given vector is more than slot count, a untime_error will be thrown.

Parameters

[out]	res	The encoded PTile
[in]	vals	The vector to encode
[in]	chainIndex	If HeContext is a CKKS context, specifies the chainIndex of the resulting PTile. otherwise, this parameter is ignored.

Exceptions

runtime_error if vals.size() > slot count

◆ encode() [4/6]

void helayers::Encoder::encode	(	PTile &	res,
		const std::vector< std::complex< double >> &	vals,
		int	chainIndex = `-1`
	)		const

Encodes the given vector of complex numbers into a PTile.

If the size of the given vector is less than slot count, the empty slots of the PTile will be set to zero. If the size of the given vector is more than slot count, a untime_error will be thrown.

Parameters

[out]	res	The encoded PTile
[in]	vals	The vector to encode
[in]	chainIndex	If HeContext is a CKKS context, specifies the chainIndex of the resulting PTile. otherwise, this parameter is ignored.

Exceptions

runtime_error if vals.size() > slot count

◆ encode() [5/6]

void helayers::Encoder::encode	(	PTile &	res,
		double	val,
		int	chainIndex = `-1`
	)		const

Encodes the given double into all slots of a PTile.

This is usually more efficient than regular encoding.

Parameters

[out]	res	The encoded PTile
[in]	val	The value to encode
[in]	chainIndex	If HeContext is a CKKS context, specifies the chainIndex of the resulting PTile. otherwise, this parameter is ignored.

◆ encode() [6/6]

void helayers::Encoder::encode	(	PTile &	res,
		int	val,
		int	chainIndex = `-1`
	)		const

Encodes the given int into all slots of a PTile.

This is usually more efficient than regular encoding.

Parameters

[out]	res	The encoded PTile
[in]	val	The value to encode
[in]	chainIndex	If HeContext is a CKKS context, specifies the chainIndex of the resulting PTile. otherwise, this parameter is ignored.

◆ encodeEncrypt() [1/4]

void helayers::Encoder::encodeEncrypt	(	CTile &	res,
		const std::vector< double > &	vals,
		int	chainIndex = `-1`
	)		const

Encodes and then encrypts the given vector into a CTile.

if the size of the given vector is less than slot count, the empty slots of the CTile will be set to zero. If the size of the given vector is more than slot count, a runtime_error will be thrown.

Parameters

[out]	res	The resulting CTile
[in]	vals	The vector to encode
[in]	chainIndex	If HeContext is a CKKS context, specifies the chainIndex of the resulting CTile. otherwise, this parameter is ignored.

Exceptions

runtime_error if vals.size() > slot count

◆ encodeEncrypt() [2/4]

void helayers::Encoder::encodeEncrypt	(	CTile &	res,
		const std::vector< int > &	vals,
		int	chainIndex = `-1`
	)		const

Encodes and then encrypts the given vector into a CTile.

if the size of the given vector is less than slot count, the empty slots of the CTile will be set to zero. If the size of the given vector is more than slot count, a untime_error will be thrown.

Parameters

[out]	res	The resulting CTile
[in]	vals	The vector to encode
[in]	chainIndex	If HeContext is a CKKS context, specifies the chainIndex of the resulting CTile. otherwise, this parameter is ignored.

Exceptions

runtime_error if vals.size() > slot count

◆ encodeEncrypt() [3/4]

void helayers::Encoder::encodeEncrypt	(	CTile &	res,
		const std::vector< long > &	vals,
		int	chainIndex = `-1`
	)		const

Encodes and then encrypts the given vector into a CTile.

if the size of the given vector is less than slot count, the empty slots of the CTile will be set to zero. If the size of the given vector is more than slot count, a untime_error will be thrown.

Parameters

[out]	res	The resulting CTile
[in]	vals	The vector to encode
[in]	chainIndex	If HeContext is a CKKS context, specifies the chainIndex of the resulting CTile. otherwise, this parameter is ignored.

Exceptions

runtime_error if vals.size() > slot count

◆ encodeEncrypt() [4/4]

void helayers::Encoder::encodeEncrypt	(	CTile &	res,
		const std::vector< std::complex< double >> &	vals,
		int	chainIndex = `-1`
	)		const

Encodes and then encrypts the given vector into a CTile.

if the size of the given vector is less than slot count, the empty slots of the CTile will be set to zero. If the size of the given vector is more than slot count, a runtime_error will be thrown.

Parameters

[out]	res	The resulting CTile
[in]	vals	The vector to encode
[in]	chainIndex	If HeContext is a CKKS context, specifies the chainIndex of the resulting CTile. otherwise, this parameter is ignored.

Exceptions

runtime_error	If vals.size() > slot count
runtime_error	If the underlying FHE scheme is a scheme that does not support complex values (such as BGV, for example).

◆ encrypt()

void helayers::Encoder::encrypt	(	CTile &	res,
		const PTile &	src
	)		const

Encrypts "src" into "res".

Parameters

[out]	res	The resulting CTile.
[in]	src	The PTile to encrypt

◆ getDecryptAddedNoisePrecision()

int helayers::Encoder::getDecryptAddedNoisePrecision ( ) const

Returns an integer indicating precision to be preserved.

Exceptions

runtime_error If the undelying library does not support decrypt added noise

◆ getDefaultScale()

double helayers::Encoder::getDefaultScale ( ) const

Returns the scale used by the encoder as set by setDefaultScale.

If no default was previously set, return the default scale define by the HeContext object.

◆ printErrorStats()

void helayers::Encoder::printErrorStats	(	CTile &	actualC,
		std::vector< double >	expectedZ,
		std::ostream &	out = `std::cout`,
		bool	asCsv = `false`
	)		const

Prints statstical information relating to the difference between "actualC" and "expectedZ".

Parameters

[in]	actualC	The CTile to decode-decrypt and to compare to expectedZ.
[in]	expectedZ	The vector of doubles to compare actualC with.
[in]	out	The ostream to print to.

◆ setDecryptAddedNoiseEnabled()

void helayers::Encoder::setDecryptAddedNoiseEnabled ( bool val )

Allows to determine whether to enable the decrypt added noise.

The default behaviour for libraries that supports this feature is to have it enabled. Decrypt added noise is relevant to CKKS scheme for the purpose of ensuring security. reference: "On the Security of Homomorphic Encryption on Approximate Numbers", Baiyu Li and Daniele Micciancio, https://eprint.iacr.org/2020/1533.pdf

Parameters

[in] val A boolean indicating whether to enable the decrypt added noise.

◆ setDecryptAddedNoisePrecision()

void helayers::Encoder::setDecryptAddedNoisePrecision ( int val )

Allows to set the level of precision to be preserved in the process of adding decrypt noise, if the decrypt added noise is enabled.

If decrypt added noise is not enabled, this value is ignored.

Parameters

[in] val An integer indicating precision to be preserved.

Exceptions

runtime_error If the undelying library does not support decrypt added noise

◆ setDefaultScale()

void helayers::Encoder::setDefaultScale ( double scale )

Default scale is a parameter relevant to CKKS-like schemes.

It is the scale used to encode values into plaintext/ciphertext. If left unset, the encoder will use the scheme's default. After setting, the encoder will use the given value. setDefaultScale sets the scale that the encoder will use henceforth.

Parameters

[in] scale The new default scale.

◆ validateChainIndex()

int helayers::Encoder::validateChainIndex ( int chainIndex ) const

checks whether a chain index is valid.

Parameters

[in] chainIndex To check its validity.

The documentation for this class was generated from the following files:

/opt/IBM/FHE-distro/ML-HElib/src/helayers/hebase/Encoder.h
/opt/IBM/FHE-distro/ML-HElib/src/helayers/hebase/Encoder.cpp

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ Encoder()

Member Function Documentation

◆ assertEquals() [1/4]

◆ assertEquals() [2/4]

◆ assertEquals() [3/4]

◆ assertEquals() [4/4]

◆ decodeComplex()

◆ decodeDouble()

◆ decodeInt()

◆ decodeLong()

◆ decrypt()

◆ decryptDecodeComplex()

◆ decryptDecodeDouble()

◆ decryptDecodeInt()

◆ decryptDecodeLong()

◆ encode() [1/6]

◆ encode() [2/6]

◆ encode() [3/6]

◆ encode() [4/6]

◆ encode() [5/6]

◆ encode() [6/6]

◆ encodeEncrypt() [1/4]

◆ encodeEncrypt() [2/4]

◆ encodeEncrypt() [3/4]

◆ encodeEncrypt() [4/4]

◆ encrypt()

◆ getDecryptAddedNoisePrecision()

◆ getDefaultScale()

◆ printErrorStats()

◆ setDecryptAddedNoiseEnabled()

◆ setDecryptAddedNoisePrecision()

◆ setDefaultScale()

◆ validateChainIndex()