Crypto++  5.6.3
Free C++ class library of cryptographic schemes
Public Member Functions | List of all members
TrapdoorFunctionBounds Class Referenceabstract

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

+ Inheritance diagram for TrapdoorFunctionBounds:

Public Member Functions

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 70 of file pubkey.h.

Member Function Documentation

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

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 RSAFunction, LUCFunction, RWFunction, ESIGNFunction, and RabinFunction.

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 86 of file pubkey.h.

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 90 of file pubkey.h.


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