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1 files changed, 58 insertions, 0 deletions

diff --git a/blumshub.h b/blumshub.h
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+#ifndef CRYPTOPP_BLUMSHUB_H
+#define CRYPTOPP_BLUMSHUB_H
+
+#include "modarith.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+class BlumGoldwasserPublicKey;
+class BlumGoldwasserPrivateKey;
+
+//! BlumBlumShub without factorization of the modulus
+class PublicBlumBlumShub : public RandomNumberGenerator,
+						   public StreamTransformation
+{
+public:
+	PublicBlumBlumShub(const Integer &n, const Integer &seed);
+
+	unsigned int GenerateBit();
+	byte GenerateByte();
+
+	void ProcessData(byte *outString, const byte *inString, unsigned int length)
+	{
+		while (length--)
+			*outString++ = *inString ^ GenerateByte();
+	}
+
+	bool IsSelfInverting() const {return true;}
+	bool IsForwardTransformation() const {return true;}
+
+protected:
+	const ModularArithmetic modn;
+	const int maxBits;
+	Integer current;
+	int bitsLeft;
+
+	friend class BlumGoldwasserPublicKey;
+	friend class BlumGoldwasserPrivateKey;
+};
+
+//! BlumBlumShub with factorization of the modulus
+class BlumBlumShub : public PublicBlumBlumShub
+{
+public:
+	// Make sure p and q are both primes congruent to 3 mod 4 and at least 512 bits long,
+	// seed is the secret key and should be about as big as p*q
+	BlumBlumShub(const Integer &p, const Integer &q, const Integer &seed);
+	
+	bool IsRandomAccess() const {return true;}
+	void Seek(dword index);
+
+protected:
+	const Integer p, q;
+	const Integer x0;
+};
+
+NAMESPACE_END
+
+#endif