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Topic
Board Development & Technical Discussion
Re: divided Pubkey -> Privkey
by
dexizer7799
on 24/04/2024, 14:29:57 UTC
Hi sir can you share real example with that library, thank you.

Let's make this simple. I'm going to use this 50bit keypar:

Initial PBK: 027f3bd8832c4ccc73a0c741b0ab204c0a6bafa5fd57c944e391d06906f6db7d5f
Initial PVK: 0x39c3e0843ac77 [1016215170690167 in decimal]

Code:
python3 PubDiv.py 027f3bd8832c4ccc73a0c741b0ab204c0a6bafa5fd57c944e391d06906f6db7d5f 10 out.txt

This generates our out.txt file with 1024 offsets. Since its a 10bit reduction in this example, at least one offset will be in the 40bit range.

I loaded the out.txt file into the BSGS algorithm and set it to run the 2^40 bit range. It found this offset:

PUB: 03720bd6f652601111001205bf748666b60903777d8bb83dc7e558d42f37c7fb5b
PVK: 0xe70f8210eb [992397627627 in decimal]

This offset is found in the line 120 of my out.txt file, so now we have everything to set up the equation:

Offset PVK = 992397627627
Total Offsets = 1024
Offset's Position = 120


For the sake of simplicity I'll run this on python:

Code:
PVK = 992397627627 * 1024 + 120 - 1
hex_PVK = hex(PVK)
print(hex_PVK)
print(PVK)

Result: 0x39c3e0843ac77, 1016215170690167 in decimal.

Hi sir it works perfectly but when range is 80 or more I cannot find because range is big to find the divided pubkey and do calculation. What can I do in that situation to solve that problem? Example I want to do calculation with 125 bit range pub key.