https://www.codingame.com/training/hard/sha-256-hash
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Created by @schachmatt,validated by @rozbrajaczpoziomow,@Karocyt and @Cmdr.Shepard.
If you have any issues, feel free to ping them.
Educational puzzle 
It’s easier to use the regular hash values first, to be able to compare partial results with the linked tutorial. Then swap for the values of the puzzle before submitting.
3 Likes
Oh, this is a tedious business, cryptography …
Thanks to the author for the work.
1 Like
Incredibly good puzzle! I’m digging it!
1 Like
I’m a bit stuck on this one can any one help. I pass the first three tests, the shorter ones. Then the longer ones I fail.
I split the message into 55 character chunks and after the chunk is encoded I add
h0 += a … though to h7 += h.
Then concat h0 - h7 for the result.
Any help would be appreciated.
Use the actual initial hash values and compare your results with https://qvault.io/cryptography/how-sha-2-works-step-by-step-sha-256/
If you go step by step you should figure out where is the problem 
2 Likes
Thanks. Got it. I mistakenly assumed the padding to 512 meant I had to break up the originally message before padding…hence the 55 character chunks. After re-reading the linked specs pseudo code I realized what I was doing.
1 Like
Hi All, Its really interesting and for me all the test case are passing but it shows only 80% and validator 5 is getting failed. I am not getting the problem exactly.
Thanks for puzzle.
The link for step by step died. Anyone know where I can find an equivalent ?