diff --git a/tools/ed25519raw.py b/tools/ed25519raw.py
index c7ad69eb85..4d16d548b0 100644
--- a/tools/ed25519raw.py
+++ b/tools/ed25519raw.py
@@ -1,3 +1,6 @@
+# orignal version downloaded from https://ed25519.cr.yp.to/python/ed25519.py
+# modified for Python 3 by Jochen Hoenicke <hoenicke@gmail.com>
+
 import hashlib
 
 b = 256
@@ -9,9 +12,9 @@ def H(m):
 
 def expmod(b,e,m):
   if e < 0:
-    raise Exception('negative exponent')
+    raise Exception("negative exponent")
   if e == 0: return 1
-  t = expmod(b,e >> 1,m)**2 % m
+  t = expmod(b,e>>1,m)**2 % m
   if e & 1: t = (t*b) % m
   return t
 
diff --git a/tools/keytool b/tools/keytool
index ebe68431fe..7eff01c3e2 100755
--- a/tools/keytool
+++ b/tools/keytool
@@ -190,7 +190,7 @@ def test():
     data = sys.argv[1].encode('utf-8')
     N = 5
     keyset = [1,3,4]
-    
+
     digest = pyblake2.blake2s(data).digest()
     print('Digest: %s' % hex(digest))
     sks = []
@@ -212,7 +212,7 @@ def test():
         print('Local commit: %s' % hex(R))
         nonces.append(r)
         commits.append(R)
-        
+
     globalPk = combine_keys([pks[i] for i in keyset])
     globalR = combine_keys([commits[i] for i in keyset])
     print('-----------------')
@@ -232,15 +232,12 @@ def test():
         print('Local sig %d: %s' % (i+1, hex(ed25519raw.encodeint(S))))
         commits.append(R)
         sigs.append(ed25519raw.encodeint(S))
-        
 
     print('-----------------')
     sig = combine_sig(globalR, [sigs[i] for i in [1,3,4]])
     print('Global sig: %s' %hex(sig))
     ed25519raw.checkvalid(sig, digest, globalPk)
     print('Valid Signature!')
-        
-        
 
 if __name__ == '__main__':
     test()