baptistecolin / itsuku Goto Github PK

So far, the merkle_tree function can only build a regular binary tree, made of 2*T-1 nodes, if the initial array X is of size 2^n.

This function (as well of the rest of the program, probably) should be amended so it can build a Merkle-tree out of an array X of arbitrary size

Ideally, each function should be accompanied with some "documentation", that is to say comments that explain clearly what are the expected inputs and ouputs, what the function does, etc

Looks like the H function in itsuku.py does not behave deterministically, which is not what we want ...

The following test fails :

sha = sha512()
sha_input = int_to_4bytes(123)
sha.update(sha_input)
assert sha.digest[:10] == H(10, sha_input)

The comparison in the assertion fails because the two string are totally different. Moreover, if you run the test again, you will see that the right-hand term in the assertion is never the same. Which is why I'm calling this "undeterministic". Meanwhile, the left-hand term remains the same frome one test to another, which is what is expected.

If you figure out what's wrong with our H function, please let us know !

As a first try, we used H everywhere the paper said to use the described F hashing function, with the intention to iterate and implement it.

Now let's iterate ! 😎