I recently stumbled across a private key with 98 characters that starts with "3". As far as I know, bitcoin private keys only starts with 5, K or L and is 51 and 52 characters long. Anyone has an ideia of what it is?
Are you certain it's a bitcoin private key? If so, maybe you encrypted it? It's definitely not a BIP38 encryption though.
Yes and no. Where I find it mentions that this is a bitcoin private key and this key was already encrypted that way.
Then we have 2 options:
1.-You are dealing with a brain wallet.
2.-You are dealing with an unknown encryption
To see if you are dealing with a Passphrase address you could use a service like this one to get the real private key.
https://brainwalletx.github.io/
And if the scenario is the second one, then to get the private key you will need to find the right way to decrypt that wallet, maybe you could get more data from the same place where you get the key.
Tried the First one, nothing. Went back to where I found the Key and managed to get the address, hash160 and public key on that place, but nothing regarding the type of encryption used there. But searching on Google, I found another person trying to decrypt a Key with 98 characters, but the Key started with E and the post didn't has the answer.