diff --git a/__pycache__/xorCorrelator.cpython-38.pyc b/__pycache__/xorCorrelator.cpython-38.pyc
index 20f9312..4e7332a 100644
Binary files a/__pycache__/xorCorrelator.cpython-38.pyc and b/__pycache__/xorCorrelator.cpython-38.pyc differ
diff --git a/xorCorrelator.py b/xorCorrelator.py
index 0270bed..b5b441f 100644
--- a/xorCorrelator.py
+++ b/xorCorrelator.py
@@ -1,4 +1,5 @@
 import secrets
+import hashlib
 
 def xor(a: bytes, b: bytes):
     if len(a)!=len(b):
@@ -21,7 +22,7 @@ def cbcXor(blocks, key: bytes, iv: bytes = None, BS=16):
         res.append(enc)
     return res
 
-def decCbcXor(blocks, key: bytes, iv: bytes = None, BS=16):
+def decCbcXor(blocks, key: bytes, iv: bytes = None, BS: int = 16):
     if len(key)!=BS:
         raise Exception("Bad key len")
     if not iv:
@@ -37,5 +38,25 @@ def decCbcXor(blocks, key: bytes, iv: bytes = None, BS=16):
         res.append(enc)
     return res
 
-def randBlocks(num: int = 64):
+def randBlocks(num: int = 64, BS: int = 16):
     return [secrets.token_bytes(16) for i in range(num)]
+
+def hashsum(blocks):
+    return hashlib.sha3_256("".join(blocks)).digest()
+
+def buildCollisionMatrix(blocks):
+    mat = []
+    for b in range(0,len(blocks)-1):
+        line = []
+        for c in range(b+1,len(blocks)):
+            block = blocks[b]
+            compr = blocks[c]
+
+            collLen = 0
+            for d in range(len(block)):
+                if block[d]!=compr[d]:
+                    break
+                collLen+=1
+            line.append(collLen)
+        mat.append(line)
+    return mat