Private Key: 9ccbcabf23e271183dbed503b43277f4c6eee9ac918cd6cda75ebb73ceb35c7d

Corresponding Public Address: 0xa73Fb234B1773ed7b115D18A1f0a15579bA2C1e1 (check for yourself on MyCrypto, for example)

One can generate the Public Key from the Private Key: 25b867253fe38ac7ed594f54b4f55fa18c49ced332fc352991e48a77ab7816c759d46cab51a59d9833cd6d958cc752ad95f10bbe469b364db2de5d3535417966

This Public Key, however, does not seem to be produce the Public Address above. Instead, after running it through keccak256, then taking the last 20 bytes, we're left with: 0xaa72e09d258da5496a7e6628e09207ec382e478a

What am I doing wrong?

1 Answer 1


You need to hash the bytes of the public key (not the public key string).

In Javascript https://runkit.com/embed/2w4f7dvkz2lg

keccak256 = require('js-sha3').keccak256;

keccak256(new Buffer('25b867253fe38ac7ed594f54b4f55fa18c49ced332fc352991e48a77ab7816c759d46cab51a59d9833cd6d958cc752ad95f10bbe469b364db2de5d3535417966', 'hex')).slice(24)


Note how the public key is put in a Buffer.

  • Thanks. I'm not working with Javascript, so this is the problem. Looks like my keccak algorithm will only accept strings. Oy.
    – EvilJordan
    Feb 18, 2018 at 9:06
  • If it's not obvious, I'm using PHP. Groan, I know. I can turn the produced Public Key in to its bytes, and confirm they match what JS libraries are seeing. So, now to pass those bytes to the hashing algorithm in a way that is acceptable, since it will only handle strings. I've attempted to simply "implode" the byte array in to a long string, but that didn't work. Any clever ideas?
    – EvilJordan
    Feb 18, 2018 at 9:36
  • 3
    Holy sweet god I got it. Just hex2bin($publicKey) before passing it in to the hash. Praise the lord. Thank you.
    – EvilJordan
    Feb 18, 2018 at 10:01
  • @EvilJordan Feel free to post your own (PHP) answer also. (It was not obvious at all that you were using PHP.)
    – eth
    Feb 28, 2018 at 6:17
  • @EvilJordan Thank you! I could kiss your feet right now lol. I have been trying to figure out exactly the same thing for 2 days
    – Zappa
    Mar 31, 2018 at 11:48

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