diff -r 7d6f2526244a -r 197a85a35cba src/net/java/otr4j/crypto/OtrCryptoEngine.java
--- a/src/net/java/otr4j/crypto/OtrCryptoEngine.java	Sun Mar 15 17:28:04 2015 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,83 +0,0 @@
-/*
- * otr4j, the open source java otr library.
- *
- * Distributable under LGPL license.
- * See terms of license at gnu.org.
- */
-
-package net.java.otr4j.crypto;
-
-import java.math.BigInteger;
-import java.security.KeyPair;
-import java.security.PrivateKey;
-import java.security.PublicKey;
-
-import javax.crypto.interfaces.DHPublicKey;
-
-/**
- * 
- * @author George Politis
- * 
- */
-public interface OtrCryptoEngine {
-
-	public static final String MODULUS_TEXT = "00FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3DC2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F83655D23DCA3AD961C62F356208552BB9ED529077096966D670C354E4ABC9804F1746C08CA237327FFFFFFFFFFFFFFFF";
-	public static final BigInteger MODULUS = new BigInteger(MODULUS_TEXT, 16);
-	public static final BigInteger BIGINTEGER_TWO = BigInteger.valueOf(2);
-	public static final BigInteger MODULUS_MINUS_TWO = MODULUS
-			.subtract(BIGINTEGER_TWO);
-
-	public static String GENERATOR_TEXT = "2";
-	public static BigInteger GENERATOR = new BigInteger(GENERATOR_TEXT, 10);
-
-	public static final int AES_KEY_BYTE_LENGTH = 16;
-	public static final int SHA256_HMAC_KEY_BYTE_LENGTH = 32;
-	public static final int DH_PRIVATE_KEY_MINIMUM_BIT_LENGTH = 320;
-	public static final byte[] ZERO_CTR = new byte[] { 0x00, 0x00, 0x00, 0x00,
-			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-			0x00 };
-
-	public static final int DSA_PUB_TYPE = 0;
-
-	public abstract KeyPair generateDHKeyPair() throws OtrCryptoException;
-
-	public abstract DHPublicKey getDHPublicKey(byte[] mpiBytes)
-			throws OtrCryptoException;
-
-	public abstract DHPublicKey getDHPublicKey(BigInteger mpi)
-			throws OtrCryptoException;
-
-	public abstract byte[] sha256Hmac(byte[] b, byte[] key)
-			throws OtrCryptoException;
-
-	public abstract byte[] sha256Hmac(byte[] b, byte[] key, int length)
-			throws OtrCryptoException;
-
-	public abstract byte[] sha1Hmac(byte[] b, byte[] key, int length)
-			throws OtrCryptoException;
-
-	public abstract byte[] sha256Hmac160(byte[] b, byte[] key)
-			throws OtrCryptoException;
-
-	public abstract byte[] sha256Hash(byte[] b) throws OtrCryptoException;
-
-	public abstract byte[] sha1Hash(byte[] b) throws OtrCryptoException;
-
-	public abstract byte[] aesDecrypt(byte[] key, byte[] ctr, byte[] b)
-			throws OtrCryptoException;
-
-	public abstract byte[] aesEncrypt(byte[] key, byte[] ctr, byte[] b)
-			throws OtrCryptoException;
-
-	public abstract BigInteger generateSecret(PrivateKey privKey,
-			PublicKey pubKey) throws OtrCryptoException;
-
-	public abstract byte[] sign(byte[] b, PrivateKey privatekey)
-			throws OtrCryptoException;
-
-	public abstract boolean verify(byte[] b, PublicKey pubKey, byte[] rs)
-			throws OtrCryptoException;
-
-	public abstract String getFingerprint(PublicKey pubKey)
-			throws OtrCryptoException;
-}