TrapdoorFunction Class Reference

Applies the trapdoor function. More...

Inheritance diagram for TrapdoorFunction:

Public Member Functions
Integer	ApplyRandomizedFunction (RandomNumberGenerator &rng, const Integer &x) const
	Applies the trapdoor function. More...
bool	IsRandomized () const
	Determines if the encryption algorithm is randomized. More...
virtual Integer	ApplyFunction (const Integer &x) const =0
	Applies the trapdoor. More...
Public Member Functions inherited from TrapdoorFunctionBounds
virtual Integer	PreimageBound () const =0
	Returns the maximum size of a message before the trapdoor function is applied. More...
virtual Integer	ImageBound () const =0
	Returns the maximum size of a representation after the trapdoor function is applied. More...
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...

Detailed Description

Applies the trapdoor function.

ApplyFunction() is the foundation for encrypting a message under a public key. Derived classes will override it at some point.

See also

TrapdoorFunctionBounds(), RandomizedTrapdoorFunction(), TrapdoorFunction(), RandomizedTrapdoorFunctionInverse() and TrapdoorFunctionInverse()

Definition at line 125 of file pubkey.h.

Member Function Documentation

ApplyRandomizedFunction()

Integer TrapdoorFunction::ApplyRandomizedFunction ( RandomNumberGenerator &  rng, const Integer &  x  ) const

inlinevirtual

Applies the trapdoor function.

Parameters

rng	a RandomNumberGenerator derived class
x	the message on which the encryption function is applied

ApplyRandomizedFunction is a generalization of encryption under a public key cryptosystem. The RandomNumberGenerator may (or may not) be required.

Internally, ApplyRandomizedFunction() calls ApplyFunction() without the RandomNumberGenerator.

Implements RandomizedTrapdoorFunction.

Definition at line 137 of file pubkey.h.

IsRandomized()

bool TrapdoorFunction::IsRandomized ( ) const

inlinevirtual

Determines if the encryption algorithm is randomized.

Returns

true if the encryption algorithm is randomized, false otherwise

If IsRandomized() returns false, then NullRNG() can be used.

Reimplemented from RandomizedTrapdoorFunction.

Definition at line 139 of file pubkey.h.

ApplyFunction()

virtual Integer TrapdoorFunction::ApplyFunction ( const Integer &  x ) const

pure virtual

Applies the trapdoor.

Parameters

x	the 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.

Implemented in RWFunction, RSAFunction_ISO, RSAFunction, RabinFunction, LUCFunction, and ESIGNFunction.

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

• pubkey.h