Crypto++  8.8
Free C++ class library of cryptographic schemes
Public Member Functions | List of all members
LUCFunction Class Reference

The LUC function. More...

+ Inheritance diagram for LUCFunction:

Public Member Functions

void Initialize (const Integer &n, const Integer &e)
 Initialize a LUC public key with {n,e}. More...
 
void BERDecode (BufferedTransformation &bt)
 
void DEREncode (BufferedTransformation &bt) const
 
Integer ApplyFunction (const Integer &x) const
 Applies the trapdoor. More...
 
Integer PreimageBound () const
 Returns the maximum size of a message before the trapdoor function is applied. More...
 
Integer ImageBound () const
 Returns the maximum size of a representation after the trapdoor function is applied. More...
 
bool Validate (RandomNumberGenerator &rng, unsigned int level) const
 Check this object for errors. More...
 
bool GetVoidValue (const char *name, const std::type_info &valueType, void *pValue) const
 Get a named value. More...
 
void AssignFrom (const NameValuePairs &source)
 Assign values to this object. More...
 
const IntegerGetModulus () const
 
const IntegerGetPublicExponent () const
 
void SetModulus (const Integer &n)
 
void SetPublicExponent (const Integer &e)
 
- Public Member Functions inherited from TrapdoorFunction
Integer ApplyRandomizedFunction (RandomNumberGenerator &rng, const Integer &x) const
 Applies the trapdoor function. More...
 
bool IsRandomized () const
 Determines if the encryption algorithm is randomized. More...
 
- Public Member Functions inherited from TrapdoorFunctionBounds
virtual Integer MaxPreimage () const
 Returns the maximum size of a message before the trapdoor function is applied bound to a public key. More...
 
virtual Integer MaxImage () const
 Returns the maximum size of a representation after the trapdoor function is applied bound to a public key. More...
 
- Public Member Functions inherited from CryptoMaterial
virtual void ThrowIfInvalid (RandomNumberGenerator &rng, unsigned int level) const
 Check this object for errors. More...
 
virtual void Save (BufferedTransformation &bt) const
 Saves a key to a BufferedTransformation. More...
 
virtual void Load (BufferedTransformation &bt)
 Loads a key from a BufferedTransformation. More...
 
virtual bool SupportsPrecomputation () const
 Determines whether the object supports precomputation. More...
 
virtual void Precompute (unsigned int precomputationStorage)
 Perform precomputation. More...
 
virtual void LoadPrecomputation (BufferedTransformation &storedPrecomputation)
 Retrieve previously saved precomputation. More...
 
virtual void SavePrecomputation (BufferedTransformation &storedPrecomputation) const
 Save precomputation for later use. More...
 
void DoQuickSanityCheck () const
 Perform a quick sanity check. More...
 
- Public Member Functions inherited from NameValuePairs
template<class T >
bool GetThisObject (T &object) const
 Get a copy of this object or subobject. More...
 
template<class T >
bool GetThisPointer (T *&ptr) const
 Get a pointer to this object. More...
 
template<class T >
bool GetValue (const char *name, T &value) const
 Get a named value. More...
 
template<class T >
GetValueWithDefault (const char *name, T defaultValue) const
 Get a named value. More...
 
CRYPTOPP_DLL std::string GetValueNames () const
 Get a list of value names that can be retrieved. More...
 
CRYPTOPP_DLL bool GetIntValue (const char *name, int &value) const
 Get a named value with type int. More...
 
CRYPTOPP_DLL int GetIntValueWithDefault (const char *name, int defaultValue) const
 Get a named value with type int, with default. More...
 
CRYPTOPP_DLL bool GetWord64Value (const char *name, word64 &value) const
 Get a named value with type word64. More...
 
CRYPTOPP_DLL word64 GetWord64ValueWithDefault (const char *name, word64 defaultValue) const
 Get a named value with type word64, with default. More...
 
template<class T >
void GetRequiredParameter (const char *className, const char *name, T &value) const
 Retrieves a required name/value pair. More...
 
CRYPTOPP_DLL void GetRequiredIntParameter (const char *className, const char *name, int &value) const
 Retrieves a required name/value pair. More...
 

Additional Inherited Members

- Static Public Member Functions inherited from NameValuePairs
static CRYPTOPP_DLL void ThrowIfTypeMismatch (const char *name, const std::type_info &stored, const std::type_info &retrieving)
 Ensures an expected name and type is present. More...
 

Detailed Description

The LUC function.

This class is here for historical and pedagogical interest. It has no practical advantages over other trapdoor functions and probably shouldn't be used in production software. The discrete log based LUC schemes defined later in this .h file may be of more practical interest.

Since
Crypto++ 2.1

Definition at line 38 of file luc.h.

Member Function Documentation

◆ Initialize()

void LUCFunction::Initialize ( const Integer n,
const Integer e 
)
inline

Initialize a LUC public key with {n,e}.

Parameters
nthe modulus
ethe public exponent

Definition at line 48 of file luc.h.

◆ ApplyFunction()

Integer LUCFunction::ApplyFunction ( const Integer x) const
virtual

Applies the trapdoor.

Parameters
xthe message on which the encryption function is applied
Returns
the message x encrypted under the public key

ApplyFunction is a generalization of encryption under a public key cryptosystem. Derived classes must implement it.

Implements TrapdoorFunction.

Definition at line 67 of file luc.cpp.

◆ PreimageBound()

Integer LUCFunction::PreimageBound ( ) const
inlinevirtual

Returns the maximum size of a message before the trapdoor function is applied.

Returns
the maximum size of a message before the trapdoor function is applied

Derived classes must implement PreimageBound().

Implements TrapdoorFunctionBounds.

Definition at line 55 of file luc.h.

◆ ImageBound()

Integer LUCFunction::ImageBound ( ) const
inlinevirtual

Returns the maximum size of a representation after the trapdoor function is applied.

Returns
the maximum size of a representation after the trapdoor function is applied

Derived classes must implement ImageBound().

Implements TrapdoorFunctionBounds.

Definition at line 56 of file luc.h.

◆ Validate()

bool LUCFunction::Validate ( RandomNumberGenerator rng,
unsigned int  level 
) const
virtual

Check this object for errors.

Parameters
rnga RandomNumberGenerator for objects which use randomized testing
levelthe level of thoroughness
Returns
true if the tests succeed, false otherwise

There are four levels of thoroughness:

  • 0 - using this object won't cause a crash or exception
  • 1 - this object will probably function, and encrypt, sign, other operations correctly
  • 2 - ensure this object will function correctly, and perform reasonable security checks
  • 3 - perform reasonable security checks, and do checks that may take a long time

Level 0 does not require a RandomNumberGenerator. A NullRNG() can be used for level 0. Level 1 may not check for weak keys and such. Levels 2 and 3 are recommended.

See also
ThrowIfInvalid()

Implements CryptoMaterial.

Reimplemented in InvertibleLUCFunction.

Definition at line 73 of file luc.cpp.

◆ GetVoidValue()

bool LUCFunction::GetVoidValue ( const char *  name,
const std::type_info &  valueType,
void *  pValue 
) const
virtual

Get a named value.

Parameters
namethe name of the object or value to retrieve
valueTypereference to a variable that receives the value
pValuevoid pointer to a variable that receives the value
Returns
true if the value was retrieved, false otherwise

GetVoidValue() retrieves the value of name if it exists.

Note
GetVoidValue() is an internal function and should be implemented by derived classes. Users should use one of the other functions instead.
See also
GetValue(), GetValueWithDefault(), GetIntValue(), GetIntValueWithDefault(), GetRequiredParameter() and GetRequiredIntParameter()

Implements NameValuePairs.

Reimplemented in InvertibleLUCFunction.

Definition at line 84 of file luc.cpp.

◆ AssignFrom()

void LUCFunction::AssignFrom ( const NameValuePairs source)
virtual

Assign values to this object.

This function can be used to create a public key from a private key.

Implements CryptoMaterial.

Reimplemented in InvertibleLUCFunction.

Definition at line 92 of file luc.cpp.


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