blumshub.h

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// blumshub.h - originally written and placed in the public domain by Wei Dai
 
 
#ifndef CRYPTOPP_BLUMSHUB_H
#define CRYPTOPP_BLUMSHUB_H
 
#include "cryptlib.h"
#include "modarith.h"
#include "integer.h"
 
NAMESPACE_BEGIN(CryptoPP)
 
 
class PublicBlumBlumShub : public RandomNumberGenerator,
                                                   public StreamTransformation
{
public:
        virtual ~PublicBlumBlumShub() {}
 
        PublicBlumBlumShub(const Integer &n, const Integer &seed);
 
        unsigned int GenerateBit();
        byte GenerateByte();
        void GenerateBlock(byte *output, size_t size);
        void ProcessData(byte *outString, const byte *inString, size_t length);
 
        bool IsSelfInverting() const {return true;}
        bool IsForwardTransformation() const {return true;}
 
protected:
        ModularArithmetic modn;
        Integer current;
        word maxBits, bitsLeft;
};
 
class BlumBlumShub : public PublicBlumBlumShub
{
public:
        virtual ~BlumBlumShub() {}
 
        BlumBlumShub(const Integer &p, const Integer &q, const Integer &seed);
 
        bool IsRandomAccess() const {return true;}
        void Seek(lword index);
 
protected:
        const Integer p, q;
        const Integer x0;
};
 
NAMESPACE_END
 
#endif