<r​ucknium:monero.social> If I use docs.getmonero.org/rpc-library/mone…rod-rpc/#get_block_header_by_height with `fill_pow_hash` = true, I can get a `pow_hash` of each block. How would I convert the hex `pow_hash` value into an integer, for example to get the value of `H` in this formula: monero.stackexchange.com/a/12046 ?

<r​ucknium:monero.social> And why do the zeros of `pow_hash` appear at the end of the hex string? In bitcoin, the zeros appear at the beginning.

parse_hash256

<r​ucknium:monero.social> Thank you.

If you want true 256 bit divisions, use boost bigint. Or div256_64 for short divisors.

it's a sequence of bytes (2 hex characters per byte)

zeroes are in the end because LSB encoded

so the first byte is the least significant byte, the last byte is the most significant byte (bits 248-255)

<r​ucknium:monero.social> This is what I have done:

<r​ucknium:monero.social> 1) Start with the original `pow_hash`, which has 64 hexadecimal "characters".

<r​ucknium:monero.social> 2) Convert this to individual "byte" elements by concatenating the pairs of hexadecimal elements, so we have 32 byte elements.

<r​ucknium:monero.social> 3) Reverse the ordering of the 32 byte elements, i.e. the put the first element last, then the second element in the penultimate place, etc.

<r​ucknium:monero.social> 4) Concatenate these bytes together, add a `0x` at the beginning, and use a function to convert this hexadecimal form into an arbitrary-precision integer.

<r​ucknium:monero.social> Is this correct? It seems to work. A large sample of blocks pass the appropriate difficulty hurdle.

<s​needlewoods_xmr:matrix.org> seems correct to me (for block: 3472006 the pow_hash: aa6f70cf7b1e67e60028e19b03ac2f8f5661c61017cd41377dee7c0000000000, integer value: 51393878524106522740461043578110141991369175320009076927949205418)

it's a 256-bit hash in little endian wire format :)

Yes, this is correct

<r​ucknium:monero.social> Thanks, all. I am learning one byte at a time :)