Added first iteration of EC code

crypto/WeierstrassCurve.java

@@ -0,0 +1,10 @@
+package crypto;
+
+import java.math.BigInteger;
+
+public class WeierstrassCurve
+{
+    public BigInteger a;
+    public BigInteger b;
+    public BigInteger mod;
+}

crypto/WeierstrassPoint.java

@@ -0,0 +1,55 @@
+package crypto;
+
+import java.math.BigInteger;
+
+public class WeierstrassPoint {
+    public BigInteger x;
+    public BigInteger y;
+    public WeierstrassCurve curve;
+    public boolean isIdentity;
+
+    public WeierstrassPoint(WeierstrassCurve curve)
+    {
+        this.x = null;
+        this.y = null;
+        this.curve = curve;
+        this.isIdentity = true;
+    }
+
+    public WeierstrassPoint(WeierstrassCurve curve, BigInteger x, BigInteger y)
+    {
+        if (!y.multiply(y).mod(curve.mod).equals(x.modPow(BigInteger.ONE.add(BigInteger.ONE).add(BigInteger.ONE), curve.mod).add(y.multiply(curve.a)).add(curve.b).mod(curve.mod)))
+        {
+            throw new ArithmeticException("Invalid points on eliptic curve");
+        }
+        this.curve = curve;
+        this.x = x;
+        this.y = y;
+        this.isIdentity = false;
+    }
+
+    public WeierstrassPoint add(WeierstrassPoint other)
+    {
+        BigInteger x, y, m;
+        if (this.isIdentity)
+            return other;
+        if (other.isIdentity)
+            return this;
+        if (this.x.equals(other.x))
+        {
+            if (this.y.equals(other.y))
+            {
+                m = this.x.multiply(this.x).add(curve.a).multiply(this.y.add(this.y).modInverse(curve.mod));
+            } else
+            {
+                return new WeierstrassPoint(this.curve);
+            }
+        } else
+        {
+            m = other.y.add(this.y.negate()).multiply(other.x.add(this.x.negate()).modInverse(curve.mod));
+        }
+        x = m.multiply(m).add(this.x.negate()).add(other.x.negate());
+        y = x.add(this.x.negate()).multiply(m).add(this.y);
+        return new WeierstrassPoint(this.curve, x, y);
+    }
+}