The secret key. More...

#include <keys.h>

Inheritance diagram for helib::SecKey:

Public Member Functions
	SecKey ()=delete

	~SecKey () override=default

	SecKey (const Context &_context)

bool	operator== (const SecKey &other) const

bool	operator!= (const SecKey &other) const

void	clear () override
	Clear all secret-key data. More...

long	ImportSecKey (const DoubleCRT &sKey, double bound, long ptxtSpace=0, long maxDegKswitch=3)

long	GenSecKey (long ptxtSpace=0, long maxDegKswitch=3)

void	GenKeySWmatrix (long fromSPower, long fromXPower, long fromKeyIdx=0, long toKeyIdx=0, long ptxtSpace=0)

void	Decrypt (NTL::ZZX &plaintxt, const Ctxt &ciphertxt) const

template<typename Scheme >
void	Decrypt (Ptxt< Scheme > &plaintxt, const Ctxt &ciphertxt, OptLong prec=OptLong()) const
	Decrypt a ciphertext into a plaintext. More...

void	Decrypt (NTL::ZZX &plaintxt, const Ctxt &ciphertxt, NTL::ZZX &f) const
	Debugging version, returns in f the polynomial before reduction modulo the ptxtSpace. More...

long	skEncrypt (Ctxt &ctxt, const NTL::ZZX &ptxt, long ptxtSpace, long skIdx) const
	Symmetric encryption using the secret key. More...

long	skEncrypt (Ctxt &ctxt, const zzX &ptxt, long ptxtSpace, long skIdx) const

long	Encrypt (Ctxt &ciphertxt, const NTL::ZZX &plaintxt, long ptxtSpace=0) const override

long	Encrypt (Ctxt &ciphertxt, const zzX &plaintxt, long ptxtSpace=0) const override

virtual void	Encrypt (Ctxt &ctxt, const EncodedPtxt &eptxt) const override

virtual void	Encrypt (Ctxt &ctxt, const EncodedPtxt_BGV &eptxt) const override

virtual void	Encrypt (Ctxt &ctxt, const EncodedPtxt_CKKS &eptxt) const override

long	genRecryptData ()
	Generate bootstrapping data if needed, returns index of key. More...

const DoubleCRT &	getRecryptKey () const
	Getter method for the recryption key. More...

void	writeTo (std::ostream &str) const
	Write out the `SecKey` object in binary format. More...

void	writeToJSON (std::ostream &str) const
	Write out the secret key (`SecKey`) object to the output stream using JSON format. More...

JsonWrapper	writeToJSON () const
	Write out the secret key (`SecKey`) object to a `JsonWrapper`. More...

void	readJSON (std::istream &str)
	Read from the stream the serialized secret key (`SecKey`) object using JSON format. More...

void	readJSON (const JsonWrapper &j)
	Read from the `JsonWrapper` the serialized secret key (`SecKey`) object. More...

std::ostream &	writeSecKeyDerivedASCII (std::ostream &str) const

template<>
void	Decrypt (Ptxt< BGV > &plaintxt, const Ctxt &ciphertxt, UNUSED OptLong prec) const

template<>
void	Decrypt (Ptxt< CKKS > &plaintxt, const Ctxt &ciphertxt, OptLong prec) const

Public Member Functions inherited from helib::PubKey
	PubKey ()=delete

	PubKey (const Context &_context)

	PubKey (const PubKey &other)
	Copy constructor. More...

virtual	~PubKey ()=default
	Default destructor. More...

bool	operator== (const PubKey &other) const

bool	operator!= (const PubKey &other) const

const Context &	getContext () const

long	getPtxtSpace () const

bool	keyExists (long keyID) const

double	getSKeyBound (long keyID=0) const
	The size of the secret key. More...

bool	isReachable (long k, long keyID=0) const
	Is it possible to re-linearize the automorphism X -> X^k See Section 3.2.2 in the design document (KeySwitchMap) More...

void	setKeySwitchMap (long keyId=0)
	Compute the reachability graph of key-switching matrices See Section 3.2.2 in the design document (KeySwitchMap) More...

long	getKSStrategy (long dim) const
	get KS strategy for dimension dim dim == -1 is Frobenius More...

void	setKSStrategy (long dim, int val)
	set KS strategy for dimension dim dim == -1 is Frobenius More...

long	Encrypt (Ctxt &ciphertxt, const NTL::ZZX &plaintxt, long ptxtSpace, bool highNoise) const

long	Encrypt (Ctxt &ciphertxt, const zzX &plaintxt, long ptxtSpace, bool highNoise) const

void	CKKSencrypt (Ctxt &ciphertxt, const NTL::ZZX &plaintxt, double ptxtSize=1.0, double scaling=0.0) const

void	CKKSencrypt (Ctxt &ciphertxt, const zzX &plaintxt, double ptxtSize=1.0, double scaling=0.0) const

template<typename Scheme >
void	Encrypt (Ctxt &ciphertxt, const Ptxt< Scheme > &plaintxt) const
	Encrypts a plaintext into a ciphertext. More...

bool	isCKKS () const

bool	isBootstrappable () const

void	reCrypt (Ctxt &ctxt) const

void	thinReCrypt (Ctxt &ctxt) const

void	writeTo (std::ostream &str) const
	Write out the `PubKey` object in binary format. More...

void	writeToJSON (std::ostream &str) const
	Write out the public key (`PubKey`) object to the output stream using JSON format. More...

JsonWrapper	writeToJSON () const
	Write out the public key (`PubKey`) object to a `JsonWrapper`. More...

void	readJSON (std::istream &str)
	In-place read from the stream the serialized public key (`PubKey`) object using JSON format. More...

void	readJSON (const JsonWrapper &j)
	In-place read from the `JsonWrapper` the serialized public key (`PubKey`) object. More...

void	hackPtxtSpace (long p2r)

template<>
void	Encrypt (Ctxt &ciphertxt, const Ptxt< BGV > &plaintxt) const

template<>
void	Encrypt (Ctxt &ciphertxt, const Ptxt< CKKS > &plaintxt) const

const std::vector< KeySwitch > &	keySWlist () const

const KeySwitch &	getKeySWmatrix (const SKHandle &from, long toID=0) const
	Find a key-switching matrix by its indexes. If no such matrix exists it returns a dummy matrix with toKeyID==-1. More...

const KeySwitch &	getKeySWmatrix (long fromSPower, long fromXPower, long fromID=0, long toID=0) const

bool	haveKeySWmatrix (const SKHandle &from, long toID=0) const

bool	haveKeySWmatrix (long fromSPower, long fromXPower, long fromID=0, long toID=0) const

const KeySwitch &	getAnyKeySWmatrix (const SKHandle &from) const
	Is there a matrix from this key to any base key? More...

bool	haveAnyKeySWmatrix (const SKHandle &from) const

const KeySwitch &	getNextKSWmatrix (long fromXPower, long fromID=0) const
	Get the next matrix to use for multi-hop automorphism See Section 3.2.2 in the design document. More...

Static Public Member Functions
static SecKey	readFrom (std::istream &str, const Context &context)
	Read from the stream the serialized `SecKey` object in binary format. More...

static SecKey	readFromJSON (std::istream &str, const Context &context)
	Read from the stream the serialized secret key (`SecKey`) object using JSON format. More...

static SecKey	readFromJSON (const JsonWrapper &j, const Context &context)
	Read from the `JsonWrapper` the serialized secret key (`SecKey`) object. More...

Static Public Member Functions inherited from helib::PubKey
static PubKey	readFrom (std::istream &str, const Context &context)
	Read from the stream the serialized `PubKey` object in binary format. More...

static PubKey	readFromJSON (std::istream &str, const Context &context)
	Read from the stream the serialized public key (`PubKey`) object using JSON format. More...

static PubKey	readFromJSON (const JsonWrapper &j, const Context &context)
	Read from the `JsonWrapper` the serialized public key (`PubKey`) object. More...

static long	ePlusR (long p)

Static Public Attributes
static constexpr std::string_view	typeName = "SecKey"
	Class label to be added to JSON serialization as object type information. More...

Static Public Attributes inherited from helib::PubKey
static constexpr std::string_view	typeName = "PubKey"
	Class label to be added to JSON serialization as object type information. More...

Friends
class	KeySwitch

std::ostream &	operator<< (std::ostream &str, const SecKey &sk)

std::istream &	operator>> (std::istream &str, SecKey &sk)

Detailed Description

The secret key.

Constructor & Destructor Documentation

◆ SecKey() [1/2]

helib::SecKey::SecKey ( )

delete

◆ ~SecKey()

helib::SecKey::~SecKey ( )

overridedefault

◆ SecKey() [2/2]

helib::SecKey::SecKey ( const Context & _context )

explicit

Member Function Documentation

◆ clear()

void helib::SecKey::clear ( )

overridevirtual

Clear all secret-key data.

Reimplemented from helib::PubKey.

◆ Decrypt() [1/5]

void helib::SecKey::Decrypt	(	NTL::ZZX &	plaintxt,
		const Ctxt &	ciphertxt
	)		const

◆ Decrypt() [2/5]

void helib::SecKey::Decrypt	(	NTL::ZZX &	plaintxt,
		const Ctxt &	ciphertxt,
		NTL::ZZX &	f
	)		const

Debugging version, returns in f the polynomial before reduction modulo the ptxtSpace.

◆ Decrypt() [3/5]

template<>

void helib::SecKey::Decrypt	(	Ptxt< BGV > &	plaintxt,
		const Ctxt &	ciphertxt,
		UNUSED OptLong	prec
	)		const

◆ Decrypt() [4/5]

template<>

void helib::SecKey::Decrypt	(	Ptxt< CKKS > &	plaintxt,
		const Ctxt &	ciphertxt,
		OptLong	prec
	)		const

◆ Decrypt() [5/5]

template<typename Scheme >

void helib::SecKey::Decrypt	(	Ptxt< Scheme > &	plaintxt,
		const Ctxt &	ciphertxt,
		OptLong	prec = `OptLong()`
	)		const

Decrypt a ciphertext into a plaintext.

Template Parameters

Scheme Encryption scheme used (must be BGV or CKKS).

Parameters

plaintxt	Plaintext into which to decrypt.
ciphertxt	Ciphertext to decrypt.
prec	`CKKS` precision to be used (must be defaulted if Scheme is `BGV`).

◆ Encrypt() [1/5]

long helib::SecKey::Encrypt	(	Ctxt &	ciphertxt,
		const NTL::ZZX &	plaintxt,
		long	ptxtSpace = `0`
	)		const

overridevirtual

Reimplemented from helib::PubKey.

◆ Encrypt() [2/5]

long helib::SecKey::Encrypt	(	Ctxt &	ciphertxt,
		const zzX &	plaintxt,
		long	ptxtSpace = `0`
	)		const

overridevirtual

Reimplemented from helib::PubKey.

◆ Encrypt() [3/5]

void helib::SecKey::Encrypt	(	Ctxt &	ctxt,
		const EncodedPtxt &	eptxt
	)		const

overridevirtual

Reimplemented from helib::PubKey.

◆ Encrypt() [4/5]

void helib::SecKey::Encrypt	(	Ctxt &	ctxt,
		const EncodedPtxt_BGV &	eptxt
	)		const

overridevirtual

Reimplemented from helib::PubKey.

◆ Encrypt() [5/5]

void helib::SecKey::Encrypt	(	Ctxt &	ctxt,
		const EncodedPtxt_CKKS &	eptxt
	)		const

overridevirtual

Reimplemented from helib::PubKey.

◆ GenKeySWmatrix()

void helib::SecKey::GenKeySWmatrix	(	long	fromSPower,
		long	fromXPower,
		long	fromKeyIdx = `0`,
		long	toKeyIdx = `0`,
		long	ptxtSpace = `0`
	)

Generate a key-switching matrix and store it in the public key. The i'th column of the matrix encrypts fromKey*B1*B2*...*B{i-1}*Q under toKey, relative to the largest modulus (i.e., all primes) and plaintext space p. Q is the product of special primes, and the Bi's are the products of primes in the i'th digit. The plaintext space defaults to 2^r, as defined by context.mod2r.

◆ genRecryptData()

long helib::SecKey::genRecryptData ( )

Generate bootstrapping data if needed, returns index of key.

◆ GenSecKey()

long helib::SecKey::GenSecKey	(	long	ptxtSpace = `0`,
		long	maxDegKswitch = `3`
	)

Key generation: This procedure generates a single secret key, pushes it onto the sKeys list using ImportSecKey from above.

◆ getRecryptKey()

const DoubleCRT& helib::SecKey::getRecryptKey ( ) const

inline

Getter method for the recryption key.

Returns: A const reference to the recryption key.

◆ ImportSecKey()

long helib::SecKey::ImportSecKey	(	const DoubleCRT &	sKey,
		double	bound,
		long	ptxtSpace = `0`,
		long	maxDegKswitch = `3`
	)

We allow the calling application to choose a secret-key polynomial by itself, then insert it into the SecKey object, getting the index of that secret key in the sKeys list. If this is the first secret-key for this object then the procedure below also generates a corresponding public encryption key. It is assumed that the context already contains all parameters.

◆ operator!=()

bool helib::SecKey::operator!= ( const SecKey & other ) const

◆ operator==()

bool helib::SecKey::operator== ( const SecKey & other ) const

◆ readFrom()

SecKey helib::SecKey::readFrom	(	std::istream &	str,
		const Context &	context
	)

static

Read from the stream the serialized SecKey object in binary format.

Parameters

str	Input `std::istream`.

Returns: The deserialized SecKey object.

◆ readFromJSON() [1/2]

SecKey helib::SecKey::readFromJSON	(	const JsonWrapper &	j,
		const Context &	context
	)

static

Read from the JsonWrapper the serialized secret key (SecKey) object.

Parameters

j	The `JsonWrapper` containing the serialized `SecKey` object.
context	The `Context` to be used.

Returns: The deserialized SecKey object.

◆ readFromJSON() [2/2]

SecKey helib::SecKey::readFromJSON	(	std::istream &	str,
		const Context &	context
	)

static

Read from the stream the serialized secret key (SecKey) object using JSON format.

Parameters

str	Input `std::istream`.
context	The `Context` to be used.

Returns: The deserialized SecKey object.

◆ readJSON() [1/2]

void helib::SecKey::readJSON ( const JsonWrapper & j )

Read from the JsonWrapper the serialized secret key (SecKey) object.

Parameters

j	The `JsonWrapper` containing the serialized `SecKey` object.

◆ readJSON() [2/2]

void helib::SecKey::readJSON ( std::istream & str )

Read from the stream the serialized secret key (SecKey) object using JSON format.

Parameters

str	Input `std::istream`.

◆ skEncrypt() [1/2]

long helib::SecKey::skEncrypt	(	Ctxt &	ctxt,
		const NTL::ZZX &	ptxt,
		long	ptxtSpace,
		long	skIdx
	)		const

Symmetric encryption using the secret key.

◆ skEncrypt() [2/2]

long helib::SecKey::skEncrypt	(	Ctxt &	ctxt,
		const zzX &	ptxt,
		long	ptxtSpace,
		long	skIdx
	)		const

◆ writeSecKeyDerivedASCII()

std::ostream & helib::SecKey::writeSecKeyDerivedASCII ( std::ostream & str ) const

◆ writeTo()

void helib::SecKey::writeTo ( std::ostream & str ) const

Write out the SecKey object in binary format.

Parameters

str	Output `std::ostream`.

◆ writeToJSON() [1/2]

JsonWrapper helib::SecKey::writeToJSON ( ) const

Write out the secret key (SecKey) object to a JsonWrapper.

Returns: The JsonWrapper.

◆ writeToJSON() [2/2]

void helib::SecKey::writeToJSON ( std::ostream & str ) const

Write out the secret key (SecKey) object to the output stream using JSON format.

Parameters

str	Output `std::ostream`.

Friends And Related Function Documentation

◆ KeySwitch

friend class KeySwitch

friend

◆ operator<<

std::ostream& operator<<	(	std::ostream &	str,
		const SecKey &	sk
	)

friend

◆ operator>>

std::istream& operator>>	(	std::istream &	str,
		SecKey &	sk
	)

friend

Member Data Documentation

◆ typeName

constexpr std::string_view helib::SecKey::typeName = "SecKey"

staticconstexpr

Class label to be added to JSON serialization as object type information.

Public Member Functions

Static Public Member Functions

Static Public Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

◆ SecKey() [1/2]

◆ ~SecKey()

◆ SecKey() [2/2]

Member Function Documentation

◆ clear()

◆ Decrypt() [1/5]

◆ Decrypt() [2/5]

◆ Decrypt() [3/5]

◆ Decrypt() [4/5]

◆ Decrypt() [5/5]

◆ Encrypt() [1/5]

◆ Encrypt() [2/5]

◆ Encrypt() [3/5]

◆ Encrypt() [4/5]

◆ Encrypt() [5/5]

◆ GenKeySWmatrix()

◆ genRecryptData()

◆ GenSecKey()

◆ getRecryptKey()

◆ ImportSecKey()

◆ operator!=()

◆ operator==()

◆ readFrom()

◆ readFromJSON() [1/2]

◆ readFromJSON() [2/2]

◆ readJSON() [1/2]

◆ readJSON() [2/2]

◆ skEncrypt() [1/2]

◆ skEncrypt() [2/2]

◆ writeSecKeyDerivedASCII()

◆ writeTo()

◆ writeToJSON() [1/2]

◆ writeToJSON() [2/2]

Friends And Related Function Documentation

◆ KeySwitch

◆ operator<<

◆ operator>>

Member Data Documentation

◆ typeName