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C# BigInteger.IsProbablePrime方法代码示例

本文整理汇总了C#中NBitcoin.BouncyCastle.Math.BigInteger.IsProbablePrime方法的典型用法代码示例。如果您正苦于以下问题:C# BigInteger.IsProbablePrime方法的具体用法?C# BigInteger.IsProbablePrime怎么用?C# BigInteger.IsProbablePrime使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在NBitcoin.BouncyCastle.Math.BigInteger的用法示例。


在下文中一共展示了BigInteger.IsProbablePrime方法的3个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C#代码示例。

示例1: GenerateSafePrimes

        /*
         * Finds a pair of prime BigInteger's {p, q: p = 2q + 1}
         * 
         * (see: Handbook of Applied Cryptography 4.86)
         */
        internal static BigInteger[] GenerateSafePrimes(int size, int certainty, SecureRandom random)
        {
            BigInteger p, q;
            int qLength = size - 1;
            int minWeight = size >> 2;

            if (size <= 32)
            {
                for (;;)
                {
                    q = new BigInteger(qLength, 2, random);

                    p = q.ShiftLeft(1).Add(BigInteger.One);

                    if (!p.IsProbablePrime(certainty))
                        continue;

                    if (certainty > 2 && !q.IsProbablePrime(certainty - 2))
                        continue;

                    break;
                }
            }
            else
            {
                // Note: Modified from Java version for speed
                for (;;)
                {
                    q = new BigInteger(qLength, 0, random);

                retry:
                    for (int i = 0; i < primeLists.Length; ++i)
                    {
                        int test = q.Remainder(BigPrimeProducts[i]).IntValue;

                        if (i == 0)
                        {
                            int rem3 = test % 3;
                            if (rem3 != 2)
                            {
                                int diff = 2 * rem3 + 2;
                                q = q.Add(BigInteger.ValueOf(diff));
                                test = (test + diff) % primeProducts[i];
                            }
                        }

                        int[] primeList = primeLists[i];
                        for (int j = 0; j < primeList.Length; ++j)
                        {
                            int prime = primeList[j];
                            int qRem = test % prime;
                            if (qRem == 0 || qRem == (prime >> 1))
                            {
                                q = q.Add(Six);
                                goto retry;
                            }
                        }
                    }

                    if (q.BitLength != qLength)
                        continue;

                    if (!q.RabinMillerTest(2, random))
                        continue;

                    p = q.ShiftLeft(1).Add(BigInteger.One);

                    if (!p.RabinMillerTest(certainty, random))
                        continue;

                    if (certainty > 2 && !q.RabinMillerTest(certainty - 2, random))
                        continue;

                    /*
                     * Require a minimum weight of the NAF representation, since low-weight primes may be
                     * weak against a version of the number-field-sieve for the discrete-logarithm-problem.
                     * 
                     * See "The number field sieve for integers of low weight", Oliver Schirokauer.
                     */
                    if (WNafUtilities.GetNafWeight(p) < minWeight)
                        continue;

                    break;
                }
            }

            return new BigInteger[] { p, q };
        }
开发者ID:woutersmit,项目名称:NBitcoin,代码行数:93,代码来源:DHParametersHelper.cs

示例2: ChooseRandomPrime

        /// <summary>Choose a random prime value for use with RSA</summary>
        /// <param name="bitlength">the bit-length of the returned prime</param>
        /// <param name="e">the RSA public exponent</param>
        /// <returns>a prime p, with (p-1) relatively prime to e</returns>
        protected virtual BigInteger ChooseRandomPrime(int bitlength, BigInteger e)
        {
            for (;;)
            {
                BigInteger p = new BigInteger(bitlength, 1, param.Random);

                if (p.Mod(e).Equals(BigInteger.One))
                    continue;

                if (!p.IsProbablePrime(param.Certainty))
                    continue;

                if (!e.Gcd(p.Subtract(BigInteger.One)).Equals(BigInteger.One))
                    continue;

                return p;
            }
        }
开发者ID:woutersmit,项目名称:NBitcoin,代码行数:22,代码来源:RsaKeyPairGenerator.cs

示例3: GenerateParameters_FIPS186_2

        protected virtual DsaParameters GenerateParameters_FIPS186_2()
        {
            byte[] seed = new byte[20];
            byte[] part1 = new byte[20];
            byte[] part2 = new byte[20];
            byte[] u = new byte[20];
            int n = (L - 1) / 160;
            byte[] w = new byte[L / 8];

            if (!(digest is Sha1Digest))
                throw new InvalidOperationException("can only use SHA-1 for generating FIPS 186-2 parameters");

            for (;;)
            {
                random.NextBytes(seed);

                Hash(digest, seed, part1);
                Array.Copy(seed, 0, part2, 0, seed.Length);
                Inc(part2);
                Hash(digest, part2, part2);

                for (int i = 0; i != u.Length; i++)
                {
                    u[i] = (byte)(part1[i] ^ part2[i]);
                }

                u[0] |= (byte)0x80;
                u[19] |= (byte)0x01;

                BigInteger q = new BigInteger(1, u);

                if (!q.IsProbablePrime(certainty))
                    continue;

                byte[] offset = Arrays.Clone(seed);
                Inc(offset);

                for (int counter = 0; counter < 4096; ++counter)
                {
                    for (int k = 0; k < n; k++)
                    {
                        Inc(offset);
                        Hash(digest, offset, part1);
                        Array.Copy(part1, 0, w, w.Length - (k + 1) * part1.Length, part1.Length);
                    }

                    Inc(offset);
                    Hash(digest, offset, part1);
                    Array.Copy(part1, part1.Length - ((w.Length - (n) * part1.Length)), w, 0, w.Length - n * part1.Length);

                    w[0] |= (byte)0x80;

                    BigInteger x = new BigInteger(1, w);

                    BigInteger c = x.Mod(q.ShiftLeft(1));

                    BigInteger p = x.Subtract(c.Subtract(BigInteger.One));

                    if (p.BitLength != L)
                        continue;

                    if (p.IsProbablePrime(certainty))
                    {
                        BigInteger g = CalculateGenerator_FIPS186_2(p, q, random);

                        return new DsaParameters(p, q, g, new DsaValidationParameters(seed, counter));
                    }
                }
            }
        }
开发者ID:woutersmit,项目名称:NBitcoin,代码行数:70,代码来源:DsaParametersGenerator.cs


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