From c1b6f60f7056eb81759fb8e4130374bae2be0ea2 Mon Sep 17 00:00:00 2001
From: Sylvain Bellemare <sylvain@ascribe.io>
Date: Tue, 17 Jan 2017 11:27:42 +0100
Subject: [PATCH] Add an exception message

---
 bigchaindb/models.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/bigchaindb/models.py b/bigchaindb/models.py
index eb6b4a59..159e9f49 100644
--- a/bigchaindb/models.py
+++ b/bigchaindb/models.py
@@ -115,7 +115,7 @@ class Transaction(Transaction):
                             .format(self.operation, allowed_operations))
 
         if not self.inputs_valid(input_conditions):
-            raise InvalidSignature()
+            raise InvalidSignature('Transaction signature is invalid.')
 
         return self