Add ECDSA Signature mechanism

requirements.txt

@@ -1 +1,2 @@
 asyncio==3.4.3
+ecdsa==0.13

v2/wallet.py

@@ -0,0 +1,27 @@
+#!/usr/bin/env python3
+import ecdsa
+
+
+class Wallet:
+
+    def __init__(self):
+        self.signing_key = None
+        self.verifying_key = None
+
+    # Generate Private and Public keys using ECDSA
+    def generate_keys(self):
+        self.signing_key = ecdsa.SigningKey.generate(curve=ecdsa.SECP256k1)
+        self.verifying_key = self.signing_key.get_verifying_key()
+
+    # Given a message string, returns signature
+    def sign_message(self, message):
+        signed_message = self.signing_key.sign(bytes(message, 'utf-8'))
+        return signed_message
+
+    # Given a signature, sender public key, and message returns if signature is valid
+    def verify_message(self, signature, sender_verifying_key, message):
+        try:
+            sender_verifying_key.verify(signature, bytes(message, 'utf-8'))
+        except:
+            return False
+        return True