diff --git a/core/src/main/java/com/google/bitcoin/crypto/DeterministicKey.java b/core/src/main/java/com/google/bitcoin/crypto/DeterministicKey.java
index 5585303c..00e33ad7 100644
--- a/core/src/main/java/com/google/bitcoin/crypto/DeterministicKey.java
+++ b/core/src/main/java/com/google/bitcoin/crypto/DeterministicKey.java
@@ -109,7 +109,7 @@ public class DeterministicKey implements Serializable {
     ECPoint getPubPoint() {
         if (publicAsPoint == null) {
             checkNotNull(privateAsFieldElement);
-            publicAsPoint = HDUtils.getEcParams().getG().multiply(privateAsFieldElement);
+            publicAsPoint = ECKey.CURVE.getG().multiply(privateAsFieldElement);
         }
         return HDUtils.compressedCopy(publicAsPoint);
     }
diff --git a/core/src/main/java/com/google/bitcoin/crypto/HDKeyDerivation.java b/core/src/main/java/com/google/bitcoin/crypto/HDKeyDerivation.java
index 32c03d0d..15280e18 100644
--- a/core/src/main/java/com/google/bitcoin/crypto/HDKeyDerivation.java
+++ b/core/src/main/java/com/google/bitcoin/crypto/HDKeyDerivation.java
@@ -16,6 +16,7 @@
 
 package com.google.bitcoin.crypto;
 
+import com.google.bitcoin.core.ECKey;
 import com.google.common.collect.ImmutableList;
 import org.spongycastle.crypto.macs.HMac;
 import org.spongycastle.math.ec.ECPoint;
@@ -66,14 +67,14 @@ public final class HDKeyDerivation {
      */
     public static DeterministicKey createMasterPrivKeyFromBytes(
             byte[] privKeyBytes, byte[] chainCode) throws HDDerivationException {
-        BigInteger privateKeyFieldElt = HDUtils.toBigInteger(privKeyBytes);
+        BigInteger privateKeyFieldElt = new BigInteger(1, privKeyBytes);
         assertNonZero(privateKeyFieldElt, "Generated master key is invalid.");
         assertLessThanN(privateKeyFieldElt, "Generated master key is invalid.");
         return new DeterministicKey(ImmutableList.<ChildNumber>of(), chainCode, null, privateKeyFieldElt, null);
     }
 
     public static DeterministicKey createMasterPubKeyFromBytes(byte[] pubKeyBytes, byte[] chainCode) {
-        return new DeterministicKey(ImmutableList.<ChildNumber>of(), chainCode, HDUtils.getCurve().decodePoint(pubKeyBytes), null, null);
+        return new DeterministicKey(ImmutableList.<ChildNumber>of(), chainCode, ECKey.CURVE.getCurve().decodePoint(pubKeyBytes), null, null);
     }
 
     /**
@@ -94,8 +95,8 @@ public final class HDKeyDerivation {
         return new DeterministicKey(
                 HDUtils.append(parent.getChildNumberPath(), childNumber),
                 rawKey.chainCode,
-                parent.hasPrivate() ? null : HDUtils.getCurve().decodePoint(rawKey.keyBytes),
-                parent.hasPrivate() ? HDUtils.toBigInteger(rawKey.keyBytes) : null,
+                parent.hasPrivate() ? null : ECKey.CURVE.getCurve().decodePoint(rawKey.keyBytes),
+                parent.hasPrivate() ? new BigInteger(1, rawKey.keyBytes) : null,
                 parent);
     }
 
@@ -115,18 +116,18 @@ public final class HDKeyDerivation {
         assert i.length == 64 : i.length;
         byte[] il = Arrays.copyOfRange(i, 0, 32);
         byte[] chainCode = Arrays.copyOfRange(i, 32, 64);
-        BigInteger ilInt = HDUtils.toBigInteger(il);
+        BigInteger ilInt = new BigInteger(1, il);
         assertLessThanN(ilInt, "Illegal derived key: I_L >= n");
         byte[] keyBytes;
         final BigInteger privAsFieldElement = parent.getPrivAsFieldElement();
         if (privAsFieldElement != null) {
-            BigInteger ki = privAsFieldElement.add(ilInt).mod(HDUtils.getEcParams().getN());
+            BigInteger ki = privAsFieldElement.add(ilInt).mod(ECKey.CURVE.getN());
             assertNonZero(ki, "Illegal derived key: derived private key equals 0.");
             keyBytes = ki.toByteArray();
         } else {
             checkArgument(!childNumber.isPrivateDerivation(), "Can't use private derivation with public keys only.");
-            ECPoint Ki = HDUtils.getEcParams().getG().multiply(ilInt).add(parent.getPubPoint());
-            checkArgument(!Ki.equals(HDUtils.getCurve().getInfinity()),
+            ECPoint Ki = ECKey.CURVE.getG().multiply(ilInt).add(parent.getPubPoint());
+            checkArgument(!Ki.equals(ECKey.CURVE.getCurve().getInfinity()),
                     "Illegal derived key: derived public key equals infinity.");
             keyBytes = HDUtils.toCompressed(Ki.getEncoded());
         }
@@ -138,7 +139,7 @@ public final class HDKeyDerivation {
     }
 
     private static void assertLessThanN(BigInteger integer, String errorMessage) {
-        checkArgument(integer.compareTo(HDUtils.getEcParams().getN()) < 0, errorMessage);
+        checkArgument(integer.compareTo(ECKey.CURVE.getN()) < 0, errorMessage);
     }
 
     private static class RawKeyBytes {
diff --git a/core/src/main/java/com/google/bitcoin/crypto/HDUtils.java b/core/src/main/java/com/google/bitcoin/crypto/HDUtils.java
index a8eff185..d7cdb9dd 100644
--- a/core/src/main/java/com/google/bitcoin/crypto/HDUtils.java
+++ b/core/src/main/java/com/google/bitcoin/crypto/HDUtils.java
@@ -16,17 +16,13 @@
 
 package com.google.bitcoin.crypto;
 
+import com.google.bitcoin.core.ECKey;
 import com.google.common.collect.ImmutableList;
-import org.spongycastle.asn1.sec.SECNamedCurves;
-import org.spongycastle.asn1.x9.X9ECParameters;
 import org.spongycastle.crypto.digests.SHA512Digest;
 import org.spongycastle.crypto.macs.HMac;
-import org.spongycastle.crypto.params.ECDomainParameters;
 import org.spongycastle.crypto.params.KeyParameter;
-import org.spongycastle.math.ec.ECCurve;
 import org.spongycastle.math.ec.ECPoint;
 
-import java.math.BigInteger;
 import java.nio.ByteBuffer;
 import java.util.Arrays;
 
@@ -37,14 +33,6 @@ public final class HDUtils {
 
     private HDUtils() { }
 
-    private static final ECDomainParameters ecParams;
-
-    static {
-        // All clients must agree on the curve to use by agreement. Bitcoin uses secp256k1.
-        X9ECParameters params = SECNamedCurves.getByName("secp256k1");
-        ecParams = new ECDomainParameters(params.getCurve(), params.getG(), params.getN(), params.getH());
-    }
-
     static HMac createHmacSha512Digest(byte[] key) {
         SHA512Digest digest = new SHA512Digest();
         HMac hMac = new HMac(digest);
@@ -64,24 +52,16 @@ public final class HDUtils {
         return hmacSha512(createHmacSha512Digest(key), data);
     }
 
-    static BigInteger toBigInteger(byte[] bytes) {
-        return new BigInteger(1, bytes);
-    }
-
     static ECPoint compressedCopy(ECPoint pubKPoint) {
-        return getCurve().createPoint(pubKPoint.getX().toBigInteger(), pubKPoint.getY().toBigInteger(), true);
-    }
-
-    static ECCurve getCurve() {
-        return getEcParams().getCurve();
+        return ECKey.CURVE.getCurve().createPoint(pubKPoint.getX().toBigInteger(), pubKPoint.getY().toBigInteger(), true);
     }
 
     static ECPoint toUncompressed(ECPoint pubKPoint) {
-        return getCurve().createPoint(pubKPoint.getX().toBigInteger(), pubKPoint.getY().toBigInteger(), false);
+        return ECKey.CURVE.getCurve().createPoint(pubKPoint.getX().toBigInteger(), pubKPoint.getY().toBigInteger(), false);
     }
 
     static byte[] toCompressed(byte[] uncompressedPoint) {
-        return compressedCopy(getCurve().decodePoint(uncompressedPoint)).getEncoded();
+        return compressedCopy(ECKey.CURVE.getCurve().decodePoint(uncompressedPoint)).getEncoded();
     }
 
     static byte[] longTo4ByteArray(long n) {
@@ -90,10 +70,6 @@ public final class HDUtils {
         return bytes;
     }
 
-    static ECDomainParameters getEcParams() {
-        return ecParams;
-    }
-
     static byte[] getBytes(ECPoint pubKPoint) {
         return compressedCopy(pubKPoint).getEncoded();
     }
diff --git a/core/src/test/java/com/google/bitcoin/crypto/HDUtilsTest.java b/core/src/test/java/com/google/bitcoin/crypto/HDUtilsTest.java
index c4ab9bc3..ce43ab89 100644
--- a/core/src/test/java/com/google/bitcoin/crypto/HDUtilsTest.java
+++ b/core/src/test/java/com/google/bitcoin/crypto/HDUtilsTest.java
@@ -1,5 +1,6 @@
 package com.google.bitcoin.crypto;
 
+import com.google.bitcoin.core.ECKey;
 import org.junit.Assert;
 import org.junit.Test;
 import org.slf4j.Logger;
@@ -119,14 +120,14 @@ public class HDUtilsTest {
                 "04ed83704c95d829046f1ac27806211132102c34e9ac7ffa1b71110658e5b9d1bdedc416f5cefc1db0625cd0c75de8192d2b592d7e3b00bcfb4a0e860d880fd1fc",
                 "042596957532fc37e40486b910802ff45eeaa924548c0e1c080ef804e523ec3ed3ed0a9004acf927666eee18b7f5e8ad72ff100a3bb710a577256fd7ec81eb1cb3");
 
-        ECDomainParameters ecp = HDUtils.getEcParams();
+        ECDomainParameters ecp = ECKey.CURVE;
         ECCurve curve = ecp.getCurve();
 
         for (String testpkStr : testPubKey) {
             byte[] testpk = Hex.decode(testpkStr);
 
-            BigInteger pubX = HDUtils.toBigInteger(Arrays.copyOfRange(testpk, 1, 33));
-            BigInteger pubY = HDUtils.toBigInteger(Arrays.copyOfRange(testpk, 33, 65));
+            BigInteger pubX = new BigInteger(1, Arrays.copyOfRange(testpk, 1, 33));
+            BigInteger pubY = new BigInteger(1, Arrays.copyOfRange(testpk, 33, 65));
 
             ECPoint ptFlat = curve.createPoint(pubX, pubY, false); // 65
             ECPoint ptComp = curve.createPoint(pubX, pubY, true);  // 33