Based on what you wrote , the private key is in hexadecimal format. The total characters should be 64 total. Looks like you added 2 there. Try removing two at the end
My guess here is you had a hexadecimal private key and added 16 "?"s to confuse anyone who got the paper. Irony is now you are the one who fell for the trick!
It's almost certainly Bitcoin Core, though I don't know why it would give the hexadecimal of the private key. That's a fairly unusual format for a private key to be in. That said, it's easy enough to write a script to try some combination of your 66 hex characters and convert it to a 32-byte private key. The WIF format has 4 bytes extra (for a total of 36 bytes or 72 hex characters) that act as a checksum, though that's encoded in Base58, so it's unlikely to be that.
Honestly, you're best off hiring someone with the 1 BTC bounty as part of it. You'll be able to tell onchain if the person lied to you and just took the bitcoin.
The really odd thing here is the 5-letter hex found in the second column of the first 4 lines. Hex almost always come in pairs as each byte is 8 bits and each hex letter is 4 bits.
So doing some math 15 bytes in first chunk, 9 bytes, second chunk. 16 bytes third chunk, 4 bytes fourth chunk. 40 bytes is too much for a private key (they're 32 bytes) and 24 could be it, I guess. I can write you a script that you can run to check if the 24 bytes come out to the address you were looking at. I'm guessing it's uncompressed SEC since it's so early, and that's a detail you're going to need to know about for address generation. DM me on Twitter if you want to try it.
There's no obvious way to get 32 bytes, which is the typical length of a private key. I guess it could be that the last 4 bytes are not anything and the first 3 chunks are 32 bytes + 4 byte checksum. If it were and you had those question marks in those places, that's 10 question marks or 40 bits that you have to roll through or 2^40 of attempts. That's about a trillion different possibilities, which is doable, especially with some GPUs. I did 2^44 in about 2 days a while back and that cost about $800 to rent the requisite GPUs if I remember correctly. So, 2^40 should be 1/16th of that, or 3 hours and $50? But there's some custom code that needs to be written to calculate the address and there's no guarantee that that's what these letters mean.
If you're in no rush, then buy this book and read it thoroughly . it will be the best thing you can do in this instance to learn how keys should be structured and how they interact with the network.
The key itself is 64 but there is a prepended version byte and 4 extra bytes of checksum at the end. This adds 5 x 2 = 10 hex chars. I'm not sure how you get to 80 but I'm trying to figure it out :)
I think those 14 question marks are the name of someone special to you.
I think you made a riddle that says: I’m gonna take away these letters and these letters only I know what they mean.
So who is the person you love that was important to you back then?
Who has a 14 letter name? What is the meaning of 14.
That is how I would think.
What I would do is trying to picture yourself back then. There is this faucet and you are sitting behind your computer.
How old were you? What was your job. Who were your loved ones?
Simulate going back and having a piece of paper. You go to the faucet. You write this down. You know this is a secret key and then you put 14 question marks. Why? Who did you think about that has 14 question marks in their name?
You mother
Your father
Your daughter
Your wife
?
Who?
Go back
If you have plenty of time. Picture yourself 13 years ago. Like in a dream.
Like a movie. Picture yourself in that situation. Job, loved ones. House. In front of a computer. A piece of paper and a pen. How does the story go? 14 letter. Maybe 7 and 7?
The wallets created pre-mnemonic times (BIP39) have to be saved with private keys directly.
So I suppose that what you have as backup is your private key, not a seed.
So open Electrum and just paste/type the whole private key you have. If is not completed, then you can say goodbye to those BTC. You will need maybe hundreds of years to guess the missing characters.
Your umbrel is useless to recover this old wallet / private key. Umbrel is a LND aezeed wallet and will not recover that old privkey.
Good luck recovering it! I wish I would have participated in that bitcoin faucet. If you can't recover it, thank you for your donation towards reducing known supply of bitcoin.
I was there too.
I still have the BTC from that faucet (but moved to a segwit/taproot new address after the BCH fork). But I never lost any control of any wallet, ever.
If you have your private key in the format you say, in order to import your key into bitcoin core, you need to convert your key into "WIF" format first.
I guess if you exclude the question marks, you should have 66 characters. However a private key has 64 characters.
One question:
What are the first 2 digits of your key? (Do not tell me of course)
If the first 2 digits are "80" (eighty) there might be a chance your key is a private key that you prepended 2 digits (80) to it.
For the process of converting to WIF, the first step is adding that number at the beggining.
In computers, large numbers are often represented in hexadecimal format. Hexadecimal uses the characters (0-9) and (A-F) which are equivalent to 0 through 15 in decimal.
If you're counting in decimal numbers you would say 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18.
If you're counting in hexadecimal numbers you would say 8, 9, A, B, C, D, E, F, 10, 11, 12.
It's important to notice that 10 in hex is not the same as 10 in decimal. This can be pretty confusing to wrap your head around but you get the idea. So, for example the hexadecimal number A455 is actually to 69,420.
When dealing with really large hex numbers it's common practice to group them into blocks of 4 characters for readability. But this grouping has no impact on the final number. Additionally, hex numbers are often prefixed with 0x just as a reminder that its hex and not decimal.
Here's an example of a Bitcoin private key format represented in hex.
A Bitcoin private key is just a really, really large number (sometimes known as a 256-bit number). But assuming you have all 64 of the hexadecimal digits you should be able to recover it I believe.
I’m reading the book Grokking Bitcoin and there they explain all these hex codes. Way above my payroll! I have to read these chapters over and over again to understand it.
Extra single byte 01 at the end of the raw private key to indicate that it should be used with a compressed public key when generating the address (I have seen this logic in old wallets.. somewhere .. don't forget that back in the day, uncompressed public keys were quite common) - that could add 2 more, for 76.
4 still missing - this is a stretch but, did sometimes people prepend the string with "wif:..." ? That would be exactly 4 more.
Is the question mark are on random places in this 80 character string ?
If yes why you wrote them ?
Or you mean characters that are not visible or damaged ?
Need some explanation to help you
I don't have an answer for you, but I do hope you get to recover all your BTC. Best of luck, and I guess things happen for a reason, the right time will come my fren
A bitcoin private key is 256 bits long, that's 32 bytes, which when represented in hexadecimal would yield 64 characters.
However I'm puzzled by the extra 2 or even the other question marks. Are they spread all over the sequence of characters? or are they kept at one side?
Oh and both Armory and Multibit were started in 2011, so this is almost certainly from bitcoin core.
01at the end of the raw private key to indicate that it should be used with a compressed public key when generating the address (I have seen this logic in old wallets.. somewhere .. don't forget that back in the day, uncompressed public keys were quite common) - that could add 2 more, for 76.