TrapdoorFunctionBounds Class Reference

Provides range for plaintext and ciphertext lengths. More...

#include <pubkey.h>

Inheritance diagram for TrapdoorFunctionBounds:

Public Member Functions
virtual	~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 message 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 message after the trapdoor function is applied bound to a public key. More...

Detailed Description

Provides range for plaintext and ciphertext lengths.

A trapdoor function is a function that is easy to compute in one direction, but difficult to compute in the opposite direction without special knowledge. The special knowledge is usually the private key.

Trapdoor functions only handle messages of a limited length or size. MaxPreimage is the plaintext's maximum length, and MaxImage is the ciphertext's maximum length.

See also

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

Definition at line 73 of file pubkey.h.

Constructor & Destructor Documentation

virtual TrapdoorFunctionBounds::~TrapdoorFunctionBounds ( )

inlinevirtual

Definition at line 76 of file pubkey.h.

Member Function Documentation

virtual Integer TrapdoorFunctionBounds::ImageBound ( ) const

pure virtual

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

Returns

the maximum size of a message after the trapdoor function is applied

Derived classes must implement ImageBound().

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

virtual Integer TrapdoorFunctionBounds::MaxImage ( ) const

inlinevirtual

Returns the maximum size of a message after the trapdoor function is applied bound to a public key.

Returns

the the maximum size of a message after the trapdoor function is applied bound to a public key

The default implementation returns ImageBound() - 1.

Definition at line 93 of file pubkey.h.

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virtual Integer TrapdoorFunctionBounds::MaxPreimage ( ) const

inlinevirtual

Returns the maximum size of a message before the trapdoor function is applied bound to a public key.

Returns

the maximum size of a message before the trapdoor function is applied bound to a public key

The default implementation returns PreimageBound() - 1.

Definition at line 89 of file pubkey.h.

virtual Integer TrapdoorFunctionBounds::PreimageBound ( ) const

pure virtual

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().

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

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

• src/cryptopp/pubkey.h