OLD BTC private key format, help!!!

[Rickorick]

I’m helping a friend recover Bitcoin from an old wallet dating back to 2010. The laptop is long gone, but luckily there’s a printed sheet with the following details:

1 Bitcoin address (confirmed to hold BTC)
1 public key (same in all entries)
3 different private key-looking strings
One is 32 characters, starts with HDr…
Two are 64 characters, start with oUC… and MHC…
3 different rmd160 hashes (possibly compressed vs uncompressed?)

All the public key and address fields are identical across the entries, which suggests these private keys might be different encodings or formats of the same key,  maybe raw hex, WIF, or Base58. This was common in early wallets or custom scripts that didn’t follow today’s standards.

Questions:
   1. Could these be the same private key in different formats (e.g., hex, WIF, Base58)?
   2. What’s the best way to decode and test which key is valid for the address?
   3. Can Electrum or another tool help me test them safely offline?

Any guidance or recommended tools would be hugely appreciate.  I’m happy to share more details privately if needed.

Thanks in advance!

[nc50lc]

3 different private key-looking strings
One is 32 characters, starts with HDr…
Two are 64 characters, start with oUC… and MHC…

None of those resemble any format of a private key;
The 32 character's length and characters isn't recognizable.
The 64 character strings don't look like ECDSA private key for having non-hexadecimal characters.
Or have you replaced the the starting characters with something random?

Questions:
   1. Could these be the same private key in different formats (e.g., hex, WIF, Base58)?
   2. What’s the best way to decode and test which key is valid for the address?
   3. Can Electrum or another tool help me test them safely offline?

1/2: Check this thread for the formats and possible ways to recover: /index.php?topic=4959742.0
3: No, it should be in the specific formats that's supported by Electrum: WIF or Mini-Private key.

[Trêvoid]

Hi, try importing each key into Electrum or Bitcoin Core.

If rejected, then decode from Base64/Base58 to hex/WIF offline.

You can also use BTCRecover for damaged or custom encoded keys.

[hd49728]

3 different private key-looking strings
One is 32 characters, starts with HDr…
Two are 64 characters, start with oUC… and MHC…

To recover a wallet, you need either its wallet file or private key or mnemonic seed.

The FinderOuter, a bitcoin recovery tool.
[overview] Recover Bitcoin from any old storage format.

Base58check version prefix and encoded result examples
https://github.com/bitcoinbook/bitcoinbook/blob/develop/ch04_keys.adoc#base58check_versions

https://en.bitcoin.it/wiki/List_of_address_prefixes

If what you have starts with either 5, K, L, you have good backup to go but you don't have it.

[Rickorick]

3 different private key-looking strings
One is 32 characters, starts with HDr…
Two are 64 characters, start with oUC… and MHC…

None of those resemble any format of a private key;
The 32 character's length and characters isn't recognizable.
The 64 character strings don't look like ECDSA private key for having non-hexadecimal characters.
Or have you replaced the the starting characters with something random?

Questions:
   1. Could these be the same private key in different formats (e.g., hex, WIF, Base58)?
   2. What’s the best way to decode and test which key is valid for the address?
   3. Can Electrum or another tool help me test them safely offline?

1/2: Check this thread for the formats and possible ways to recover: /index.php?topic=4959742.0
3: No, it should be in the specific formats that's supported by Electrum: WIF or Mini-Private key.

This was back in 2010 when everything was non standard. He likely used cli tools to generate the key. Is it possible that they may be custom encoded?

I don't know how to attach an image here.

[nc50lc]

-snip-

This was back in 2010 when everything was non standard. He likely used cli tools to generate the key. Is it possible that they may be custom encoded?

There's a possibility of that since WIF isn't a thing back then, but most old tools export the keys in 64 hex characters.
He should remember the tool that he have used to export or create those.

Or ask around for old tools that people may have used to export private keys from wallet.dat files before this PR.

I don't know how to attach an image here.

Just upload it to talkimg.com, then share the img BBCODE in your reply.
Do not screenshot the possible private keys though.

[ethex]

3 different private key-looking strings
One is 32 characters, starts with HDr…
Two are 64 characters, start with oUC… and MHC…

None of those resemble any format of a private key;
The 32 character's length and characters isn't recognizable.
The 64 character strings don't look like ECDSA private key for having non-hexadecimal characters.
Or have you replaced the the starting characters with something random?

Questions:
   1. Could these be the same private key in different formats (e.g., hex, WIF, Base58)?
   2. What’s the best way to decode and test which key is valid for the address?
   3. Can Electrum or another tool help me test them safely offline?

1/2: Check this thread for the formats and possible ways to recover: /index.php?topic=4959742.0
3: No, it should be in the specific formats that's supported by Electrum: WIF or Mini-Private key.

This was back in 2010 when everything was non standard. He likely used cli tools to generate the key. Is it possible that they may be custom encoded?

I don't know how to attach an image here.

You can use img tags to attach an image

[Cricktor]

I’m helping a friend recover Bitcoin from an old wallet dating back to 2010. The laptop is long gone, but luckily there’s a printed sheet with the following details:
...

Does your "friend" remember which wallet software it was? It might be possible to figure it out, because back in 2010 there weren't terribly many wallets available. It could involve a lengthy research in this forum digging through old topics and posts.

No backups available? No hand-written notes?

Well, if your friend used exotic cli tools, he should've documented what he used. Actually he should've documented stuff regardless of what he used. All too often it shows that after considerable time has passed, devices died and whatnot else, people don't remember what they have done or used and how.

I mention this here not to poke a finger in wounds but to highlight the importance of proper documentation for valuable assets and how they're stored and how they can be restored. Don't forget to actually test if you can restore a wallet from backed up details. If you don't have this, it's only a matter of time when it will shoot you in your foot.