Applications of FPGA vs GPU?

[Gerrifessy]

Hello all,

I have a question regarding FPGA performance vs GPU (I've reviewed it). I’m trying to recover lost bitcoins that I mined in the early days. I knew it was important to keep the private key but in the end I somehow managed to lose my private key but I still have 24 out of 32 bytes of my private key, found on half a piece of paper when I printed that private key back in 2012.

So I have 24 bytes out of the total 32 bytes of my private key. I can only recover this by brute forcing. But I’m not familiar with FPGA and I’m totally unsure how fast they would be able to do these calculations.

The required calculations would be incrementing a 256 bit number (starting at the lower boundary of the 24 bytes out of the 32 I have), doing the elliptic curve calculation in order to get a public key and then ripemd160(sha256(publicKey)) and compare the resulting hash160 with my address hash160. If they are equal I found my private key and I can recover my bitcoins.

Do you think an FPGA like this could do this in a reasonable time? I don't mind if it takes a year for example but there is no point in doing this if it takes > 100 years... I’m trying to figure out if it’s worth going with an FPGA for this in order to recover +- 110 BTC. Maybe I need too many FPGA’s and it might not be worth it… Or do you think high end GPU’s like an nvidia 1080TI will be better suited for the job?

If you think an FPGA can certainly be used for this. What kind of FPGA am I looking at, how much do they cost and how many would I need?

Thank you for your time.

[JColvin]

Hi @Gerrifessy,

The short answer is that this is probably not worth the effort, based on these two articles, https://www.nandland.com/articles/using-your-fpga-to-mine-for-bitcoins.html and https://digilent.com/blog/what-is-the-deal-with-cryptocurrency-and-fpga/. Perhaps since you have not as many bytes an FPGA could be okay for some number crunching in a reasonable timeframe, but I do not have any real experience to give more detail than that.

Thanks,
JColvin

[Mario875]

if you have the first 24 bytes, that means out of your 256 bits you still have 64-bits unknown. The RC5 distributed computing network took almost 5 years to brute force a 64-bit encryption according to this article... https://blog.codinghorror.com/brute-force-key-attacks-are-for-dummies/

 

A single FPGA or even a small cluster would likely take much longer.