2 files changed, 6 insertions, 4 deletions
diff --git a/crypto/src/asn1/cryptopro/ECGOST3410NamedCurves.cs b/crypto/src/asn1/cryptopro/ECGOST3410NamedCurves.cs
index ccf3155cf..f4a3fce64 100644
--- a/crypto/src/asn1/cryptopro/ECGOST3410NamedCurves.cs
+++ b/crypto/src/asn1/cryptopro/ECGOST3410NamedCurves.cs
@@ -121,14 +121,14 @@ namespace Org.BouncyCastle.Asn1.CryptoPro
                 mod_p, // p
                 new BigInteger("C2173F1513981673AF4892C23035A27CE25E2013BF95AA33B22C656F277E7335", 16), // a
                 new BigInteger("295F9BAE7428ED9CCC20E7C359A9D41A22FCCD9108E17BF7BA9337A6F8AE9513", 16), // b
-                mod_q, BigInteger.One);
+                mod_q, BigInteger.Four);
 
             ecParams = new ECDomainParameters(
                 curve,
                 curve.CreatePoint(
                     new BigInteger("91E38443A5E82C0D880923425712B2BB658B9196932E02C78B2582FE742DAA28", 16), // x
                     new BigInteger("32879423AB1A0375895786C4BB46E9565FDE0B5344766740AF268ADB32322E5C", 16)), // y
-                mod_q, BigInteger.One);
+                mod_q, BigInteger.Four);
 
             parameters[RosstandartObjectIdentifiers.id_tc26_gost_3410_12_256_paramSetA] = ecParams;
 
@@ -172,14 +172,14 @@ namespace Org.BouncyCastle.Asn1.CryptoPro
                 mod_p, // p
                 new BigInteger("DC9203E514A721875485A529D2C722FB187BC8980EB866644DE41C68E143064546E861C0E2C9EDD92ADE71F46FCF50FF2AD97F951FDA9F2A2EB6546F39689BD3", 16), // a
                 new BigInteger("B4C4EE28CEBC6C2C8AC12952CF37F16AC7EFB6A9F69F4B57FFDA2E4F0DE5ADE038CBC2FFF719D2C18DE0284B8BFEF3B52B8CC7A5F5BF0A3C8D2319A5312557E1", 16), // b
-                mod_q, BigInteger.One);
+                mod_q, BigInteger.Four);
 
             ecParams = new ECDomainParameters(
                 curve,
                 curve.CreatePoint(
                     new BigInteger("E2E31EDFC23DE7BDEBE241CE593EF5DE2295B7A9CBAEF021D385F7074CEA043AA27272A7AE602BF2A7B9033DB9ED3610C6FB85487EAE97AAC5BC7928C1950148", 16), // x
                     new BigInteger("F5CE40D95B5EB899ABBCCFF5911CB8577939804D6527378B8C108C3D2090FF9BE18E2D33E3021ED2EF32D85822423B6304F726AA854BAE07D0396E9A9ADDC40F", 16)), // y
-                mod_q, BigInteger.One);
+                mod_q, BigInteger.Four);
 
             parameters[RosstandartObjectIdentifiers.id_tc26_gost_3410_12_512_paramSetC] = ecParams;
 
diff --git a/crypto/src/math/BigInteger.cs b/crypto/src/math/BigInteger.cs
index a182c43e8..997f0bbea 100644
--- a/crypto/src/math/BigInteger.cs
+++ b/crypto/src/math/BigInteger.cs
@@ -134,6 +134,7 @@ namespace Org.BouncyCastle.Math
         public static readonly BigInteger One;
         public static readonly BigInteger Two;
         public static readonly BigInteger Three;
+        public static readonly BigInteger Four;
         public static readonly BigInteger Ten;
 
         //private readonly static byte[] BitCountTable =
@@ -207,6 +208,7 @@ namespace Org.BouncyCastle.Math
             One = SMALL_CONSTANTS[1];
             Two = SMALL_CONSTANTS[2];
             Three = SMALL_CONSTANTS[3];
+            Four = SMALL_CONSTANTS[4];
             Ten = SMALL_CONSTANTS[10];
 
             radix2 = ValueOf(2);