Crypto++  5.6.3
Free C++ class library of cryptographic schemes
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MersenneTwister< K, M, N, F, S > Class Template Reference

Mersenne Twister class for Monte-Carlo simulations. More...

+ Inheritance diagram for MersenneTwister< K, M, N, F, S >:

Public Member Functions

 MersenneTwister (unsigned long seed=S)
 Construct a Mersenne Twister. More...
 
void GenerateBlock (byte *output, size_t size)
 Generate random array of bytes. More...
 
word32 GenerateWord32 (word32 min=0, word32 max=0xffffffffL)
 Generate a random 32-bit word in the range min to max, inclusive. More...
 
void DiscardBytes (size_t n)
 Generate and discard n bytes. More...
 
virtual void IncorporateEntropy (const byte *input, size_t length)
 Update RNG state with additional unpredictable values. More...
 
virtual bool CanIncorporateEntropy () const
 Determines if a generator can accept additional entropy. More...
 
virtual byte GenerateByte ()
 Generate new random byte and return it. More...
 
virtual unsigned int GenerateBit ()
 Generate new random bit and return it. More...
 
virtual void GenerateIntoBufferedTransformation (BufferedTransformation &target, const std::string &channel, lword length)
 Generate random bytes into a BufferedTransformation. More...
 
template<class IT >
void Shuffle (IT begin, IT end)
 Randomly shuffle the specified array. More...
 
virtual std::string AlgorithmName () const
 Provides the name of this algorithm. More...
 
virtual ClonableClone () const
 Copies this object. More...
 

Detailed Description

template<unsigned int K, unsigned int M, unsigned int N, unsigned int F, unsigned long S>
class MersenneTwister< K, M, N, F, S >

Mersenne Twister class for Monte-Carlo simulations.

Template Parameters
KMagic constant
MPeriod parameter
NSize of the state vector
FMultiplier constant
SSefault seed

Provides the MersenneTwister implementation. The class is a header-only implementation

Definition at line 26 of file mersenne.h.

Constructor & Destructor Documentation

template<unsigned int K, unsigned int M, unsigned int N, unsigned int F, unsigned long S>
MersenneTwister< K, M, N, F, S >::MersenneTwister ( unsigned long  seed = S)
inline

Construct a Mersenne Twister.

Parameters
seed32-bit seed

Defaults to template parameter S due to changing algorithm parameters over time

Definition at line 33 of file mersenne.h.

Member Function Documentation

template<unsigned int K, unsigned int M, unsigned int N, unsigned int F, unsigned long S>
void MersenneTwister< K, M, N, F, S >::GenerateBlock ( byte *  output,
size_t  size 
)
inlinevirtual

Generate random array of bytes.

Parameters
outputbyte buffer
sizelength of the buffer, in bytes

Bytes are written to output in big endian order. If output length is not a multiple of word32, then unused bytes are not accumulated for subsequent calls to GenerateBlock. Rather, the unused tail bytes are discarded, and the stream is continued at the next word32 boundary from the state array.

Reimplemented from RandomNumberGenerator.

Definition at line 47 of file mersenne.h.

References ByteReverse().

template<unsigned int K, unsigned int M, unsigned int N, unsigned int F, unsigned long S>
word32 MersenneTwister< K, M, N, F, S >::GenerateWord32 ( word32  min = 0,
word32  max = 0xffffffffL 
)
inlinevirtual

Generate a random 32-bit word in the range min to max, inclusive.

Returns
random 32-bit word in the range min to max, inclusive

If the 32-bit candidate is not within the range, then it is discarded and a new candidate is used.

Reimplemented from RandomNumberGenerator.

Definition at line 93 of file mersenne.h.

References BitPrecision(), and Crop().

template<unsigned int K, unsigned int M, unsigned int N, unsigned int F, unsigned long S>
void MersenneTwister< K, M, N, F, S >::DiscardBytes ( size_t  n)
inlinevirtual

Generate and discard n bytes.

Parameters
nthe number of bytes to discard, rounded up to a word32 size

If n is not a multiple of word32, then unused bytes are not accumulated for subsequent calls to GenerateBlock. Rather, the unused tail bytes are discarded, and the stream is continued at the next word32 boundary from the state array.

Reimplemented from RandomNumberGenerator.

Definition at line 115 of file mersenne.h.

References RoundUpToMultipleOf().

virtual void RandomNumberGenerator::IncorporateEntropy ( const byte *  input,
size_t  length 
)
inlinevirtualinherited

Update RNG state with additional unpredictable values.

Parameters
inputthe entropy to add to the generator
lengththe size of the input buffer
Exceptions
NotImplemented

A generator may or may not accept additional entropy. Call CanIncorporateEntropy() to test for the ability to use additional entropy.

If a derived class does not override IncorporateEntropy(), then the base class throws NotImplemented.

Reimplemented in ClassNullRNG, AutoSeededX917RNG< BLOCK_CIPHER >, RDSEED, RDRAND, and RandomPool.

Definition at line 1096 of file cryptlib.h.

Referenced by DL_SignerBase< SCHEME_OPTIONS::Element >::SignAndRestart().

virtual bool RandomNumberGenerator::CanIncorporateEntropy ( ) const
inlinevirtualinherited

Determines if a generator can accept additional entropy.

Returns
true if IncorporateEntropy() is implemented

Reimplemented in ClassNullRNG, AutoSeededX917RNG< BLOCK_CIPHER >, and RandomPool.

Definition at line 1104 of file cryptlib.h.

Referenced by DL_SignerBase< SCHEME_OPTIONS::Element >::SignAndRestart().

byte RandomNumberGenerator::GenerateByte ( )
virtualinherited

Generate new random byte and return it.

Returns
a random 8-bit byte

Default implementation calls GenerateBlock() with one byte.

All generated values are uniformly distributed over the range specified within the the contraints of a particular generator.

Reimplemented in ClassNullRNG, and PublicBlumBlumShub.

Definition at line 294 of file cryptlib.cpp.

unsigned int RandomNumberGenerator::GenerateBit ( )
virtualinherited

Generate new random bit and return it.

Returns
a random bit

The default implementation calls GenerateByte() and return its lowest bit.

All generated values are uniformly distributed over the range specified within the the contraints of a particular generator.

Reimplemented in ClassNullRNG, and PublicBlumBlumShub.

Definition at line 289 of file cryptlib.cpp.

Referenced by TestDataNameValuePairs::GetVoidValue().

void RandomNumberGenerator::GenerateIntoBufferedTransformation ( BufferedTransformation target,
const std::string &  channel,
lword  length 
)
virtualinherited

Generate random bytes into a BufferedTransformation.

Parameters
targetthe BufferedTransformation object which receives the bytes
channelthe channel on which the bytes should be pumped
lengththe number of bytes to generate

The default implementation calls GenerateBlock() and pumps the result into the DEFAULT_CHANNEL of the target.

All generated values are uniformly distributed over the range specified within the the contraints of a particular generator.

Note
A derived generator must override either GenerateBlock() or GenerateIntoBufferedTransformation(). They can override both, or have one call the other.

Reimplemented in ClassNullRNG, AutoSeededX917RNG< BLOCK_CIPHER >, X917RNG, and RandomPool.

Definition at line 347 of file cryptlib.cpp.

References BufferedTransformation::ChannelPut(), SecBlock< T, A >::size(), and UnsignedMin().

template<class IT >
void RandomNumberGenerator::Shuffle ( IT  begin,
IT  end 
)
inlineinherited

Randomly shuffle the specified array.

Parameters
beginan iterator to the first element in the array
endan iterator beyond the last element in the array

The resulting permutation is uniformly distributed.

Definition at line 1159 of file cryptlib.h.

References GetByte(), and NullRNG().

virtual std::string Algorithm::AlgorithmName ( ) const
inlinevirtualinherited

Provides the name of this algorithm.

Returns
the standard algorithm name

The standard algorithm name can be a name like AES or AES/GCM. Some algorithms do not have standard names yet. For example, there is no standard algorithm name for Shoup's ECIES.

Note
AlgorithmName is not universally implemented yet

Reimplemented in AuthenticatedSymmetricCipher, SignatureVerificationFilter, SignerFilter, AuthenticatedDecryptionFilter, HashVerificationFilter, HashFilter, StreamTransformationFilter, ClassNullRNG, BitBucket, RDSEED, DH_Domain< GROUP_PARAMETERS, COFACTOR_OPTION >, HMAC< T >, RDRAND, CRC32, GCM_Base, Adler32, EAX_Base, CCM_Base, SHA3, and VMAC_Base.

Definition at line 488 of file cryptlib.h.

Referenced by VariableRounds< 6, 2 >::StaticGetDefaultRounds().

virtual Clonable* Clonable::Clone ( ) const
inlinevirtualinherited

Copies this object.

Returns
a copy of this object
Exceptions
NotImplemented
Note
this is not implemented by most classes
See also
NotCopyable

Definition at line 464 of file cryptlib.h.


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