1

The Zokrates tutorial here starts with calculating the SHA256 hash of (the number) 5.

The hex representation of the result is shown at the bottom here:

enter image description here

However, I could not reproduce this on my ubuntu 18.04 command line:

(venv3.6) ~/zokrates_tutorial$ echo 5 | sha256sum
f0b5c2c2211c8d67ed15e75e656c7862d086e9245420892a7de62cd9ec582a06  -

So what's going on here?

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So, I found a convincing verification via this link.

In python there exists a function that turns a hex string into a byte representation like so:

>>> preimage = bytes.fromhex('00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 05')

from which then the hex digest can be computed:

>>> hashlib.sha256(preimage).hexdigest()
'c6481e22c5ff4164af680b8cfaa5e8ed3120eeff89c4f307c4a6faaae059ce10'

which is indeed the same a in the tutorial.

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