The FinderOuter, a bitcoin recovery tool (v0.19.1 2024-01-24)

[Coding Enthusiast]

Table of Contents

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Introduction How to use Features Links To Do List Updates

Introduction
The FinderOuter is a bitcoin recovery tool that focuses on making the recovery process easy for everyone with any level of technical knowledge. It uses a simple user interface with a list of recovery options. Each option has an explanation and many hints helping user figure out what is needed. It always consist of filling some text boxes and selecting some options and finally clicking the Find button. This eliminates the need to read long guide pages on how to use the application. Each option also has some example cases that can show a simple preview of how each option should be filled for different cases.
FinderOuter is specialized for maximum efficiency, each recovery option and their parts are written from scratch and all those parts down to the basic cryptography used (such as SHA, ECC,...) are specialized for that operation.

Thanks to .Net core and AvaloniaUI FinderOuter can run on all operating systems.
This project is written fully in C# and is 100% open source and will always remain free to use. You can make a donation if you found this tool useful..
FinderOuter is still in beta and under development. New features are slowly added and everything is optimized.
Contribution is always welcome. Please report any bugs you find or any improvement suggestions you have by creating a new issue.


Quick guide

• Select an option from this list depending on what you want to recover
• Read the instructions
• Fill in the required information
• Select appropriate available options according to the entered data
• There are some useful advanced options to speed up the recovery
• Click Find button
• See the progress and the reports
• Progressbar showing the progress percentage shows up for options that use multi-threading (take more than a couple of seconds to complete)
• All recovery options come with examples, click this button repeatedly to cycle through them
• Some parts have a help button that brings up the respective FinderOuter knowledge base page

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Features
1. Message signature verification
User can enter a message signature here to verify it. In case there is a problem with the message (except being an actually invalid signature), the code can search to find the common issues that some signing tools have and fix them.

2. Missing Base-58 characters
This option can be used to recover any base-58 encoded string with a checksum that is missing some characters. For example a damaged paper wallet where some characters are erased/unreadable. The position of missing characters must be known.
It works for (1) WIFs (Base-58 encoded private key) (2) Addresses (Base-58 encoded P2PKH or P2SH address) (3) BIP-38 (Base-58 encoded encrypted private key).

3. Missing Base-16 characters
This option is similar to previous feature but works for base-16 (hexadecimal) private keys. Since there is no checksum in this encoding it requires an additional input to check each permutation against. It accepts any address type and public keys. This option is slower in comparison because it uses ECC and that is not yet optimized.

4. Missing mini-privatekey characters
This option is similar to 2 and 3 but works for mini-privatekeys (eg. SzavMBLoXU6kDrqtUVmffv). It requires the corresponding address or public key of the minikey to check each possible key against, as a result it is also slower since it depends on ECC and has 2 additional hashes.

5. Missing mnomonic (seed) words
This option works for both BIP-39 and Electrum mnemonics that have some missing words. It requires knowing one child (private/public) key or address created from that seed and the exact derivation path of it.

6. Missing mnemonic passphrase
This option is used to recover the extension words (aka passphrase) used in mnemonics. It works for both BIP-39 and Electrum mnemonics algorithms. The available passphrase recovery modes are:
a. Alphanumeric: This is when the passphrase consists of letter, numbers and symbols and is random. Example: OT!pA?8i
b. CustomChars: This mode allows user to define their own set of characters to be used in the passphrase. c. soon

7. Missing BIP-38 password
This option can recover passwords used in encrypting bitcoin private keys using the BIP-38 proposal. The available password recovery modes are the same as mnemonic passphrase option.

8. Missing BIP-32 derivation path
This option could be used to find derivation path of a child key (private key, public key or the address) by having the mnemonic or the extended master keys (xprv or xpub). It only checks a hard-coded list of popular derivation paths.

9. Missing characters in Armory recovery phrase
This option is used to recover Armory paper backups (containing 2 or 4 lines of 36 characters in Base-16 with custom char-set) that are missing some of their characters. Since the last 4 characters of each line is the checksum this option can be very fast (1 trillion keys/sec) if the checksum is available or extremely slow (100 key/sec) if not.

10. Missing string encoding
This option could be used to determine the encoding of an arbitrary text. It currently supports Base-16, Base-43, Base-58, Base-58 with checksum and Base-64. All inputs will be converted to hexadecimal.
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Links
Source code on GitHub: https://github.com/Coding-Enthusiast/FinderOuter
Want to help?
Review the code and leave your feedback in this topic about the code, features any possible bug(s), ...
Contributions are always welcome. Here is the conventions that FinderOuter adheres to.

If You found this tool helpful consider making a donation:
1Q9swRQuwhTtjZZ2yguFWk7m7pszknkWyk
bc1q3n5t9gv40ayq68nwf0yth49dt5c799wpld376s
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To Do List (aka future features!)
See roadmap here: https://github.com/Coding-Enthusiast/FinderOuter/issues/47

• [ ]Optimize, Optimize and more Optimize.
• [ ]Utilize SIMD.
• [ ]Add support for other base-58 strings such as extended private keys.
• [X]Add BIP32 path finder.
• [X]Add password recovery.
• [X]Add BIP-39 passphrase recovery.
• [X]Add BIP-38 password recovery.

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[1713934584]

1713934584

[Coding Enthusiast]

Major Updates (see commits on github for details)

• [2020-01-01] Initial Release of Beta (0.1.0) Happy New Year!
• [2020-02-19] v 0.1.1 finding private key with 3 missing characters at unknown locations.
• [2020-03-10] v 0.1.2 recovery of hex private keys is now supported.
• [2020-05-11] v 0.2.0 recovery of addresses and BIP-38 keys are now supported + move backend to Bitcoin.Net.
• [2020-05-30] v 0.3.0 recovery of mini private keys is now supported.
• [2020-06-30] v 0.4.0 recovery of BIP-39 mnemonics is now supported.
• [2020-07-23] v 0.4.1 adds example button.
• [2020-09-17] v 0.5.0 the parallelism update increasing speed from 10% to more than 1800% utilizing the whole CPU power.
• [2020-12-24] v 0.6.0 recovery of Electrum mnemonic and more options in Base16 recovery.
• [2021-02-02] v 0.7.0 UI improvements
• [2021-03-20] v 0.8.0 recover BIP-32 path and Armory backup phrases
• [2021-04-05] v 0.9.0 find encoding of a string, added help and knowledge base windows
• [2021-05-05] v 0.10.0 huge optimization by changing ECC and solving issue #9
• [2021-06-13] v 0.11.0 optimizing SHA and Base58 algorithm
• [2021-08-13] v 0.12.0 recovering mnemonic passphrase is now supported.
• [2021-08-19] v 0.12.1 bug fix in missing mnemonic passphrase option.
• [2022-02-02] v 0.13.0 recovering BIP38 passwords is now supported.
• [2022-03-07] v 0.14.0 general code improvement.
• [2022-05-19] v 0.15.0 introduced search space.
• [2022-09-19] v 0.16.0 introduced search space for BIP38 passphrases.
• [2023-02-27] v 0.17.0 bug fixes and code improvement (pre-release for 1.0).
• [2023-06-23] v 0.18.0 bug fixes and code improvement + 2 new small features (pre-release for 1.0).
• [2023-11-15] v 0.19.0 new option to limit number of threads to use (pre-release for 1.0).
• [2024-01-24] v 0.19.1 small but critical bug fix (pre-release for 1.0).

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Complete change-log: https://github.com/Coding-Enthusiast/FinderOuter/blob/master/CHANGELOG.md

[ABCbits]

I see you're switching to .NET Core and user don't need to deal with dependency at all. I can even run it on niche Linux distro

As for finding missing Base58, IMO you should consider scenario when user missing few character but don't know location of the missing character.

[Coding Enthusiast]

I see you're switching to .NET Core and user don't need to deal with dependency at all. I can even run it on niche Linux distro

Yeah, netcore has been a fantastic decision by Microsoft. It is not only runs on multiple OS/platforms but also is fully open source and also highly optimized.
I'll slowly migrate all of my previous projects (eg. transaction tool) to netcore too but as a new project called Denovo.

As for finding missing Base58, IMO you should consider scenario when user missing few character but don't know location of the missing character.

Thanks for your feedback. I'll add this to my to-do list.

[buwaytress]

Cool beans. I suppose we'll just have to look for those inevitable threads of people who've lost access and see if this tool will help them the way it's designed to (opening it up, putting in a line and clicking go). Still needs a bit of basic understanding for the casual user though (that includes people like me).

[Coding Enthusiast]

Next release (0.2.0) is probably going to take some more time as I am busy releasing Denovo (20k LoC so far) these days and the next feature requires optimization of ECC. However I keep releasing the code which could be used if you compile it yourself.
New feature is Missing Mnemonic which is when you have a seed phrase missing a couple of words.
There is also a changelog which helps you follow all the changes (and commits).
There is also a continuous integration workflow to ensure successful builds and deployment.

you should consider scenario when user missing few character but don't know location of the missing character.

I haven't been able to come up with a way to generalize this. The alternative is to hard code it for each case individually (one method for missing 1 char, another for 2 and so on) which I don't really like. I'm going to place it in an issue #1 until I can come up with a neat solution.

[bitmover]

• Verifying bitcoin message signatures and in case of failure it can try to find where the problem was.

Will it verify messages from Segwit addresses?
It is still a problem, only Electrum does that until now, as far as I know.

I am only able to sign from legacy addresses using most software

[Coding Enthusiast]

Will it verify messages from Segwit addresses?

Of course it will.
The 3 basic script types used in signing are supported: P2PKH (address starting with 1), P2WPKH (address starting with bc1) and P2SH-P2WPKH (address starting with 3).
I don't think there is anything else left apart from BIP-322 which I will add soon.

[LoyceV]

Quote from another topic:

Thanks is there a tool i can use to recover ? as i must have missed a few characters off or could someone help me via private message  as i do not want to disclose it on here !!

You could use The FinderOuter. Compile it from source code or download the released version, run it offline. The program only has 2 options for now and you need the second option ("Missing Base58"). I believe the rest is self explanatory.
It should take a second to find the right key(s) with 3 missing characters.

I'm trying to recover JBRai's private key with 49 out of 52 characters known. I've installed The FinderOuter (in a VM), but it asks for the locations of the missing characters.
Any chance you can add a loop to search all possible locations for the 3 missing characters? That is, assuming the rest of JBRai's key is correct.

I've tested it with a known key: it takes about 2 seconds to find 3 missing characters. To do the same on 3 unknown locations would take about 58^3 times longer, which means several days, but it'll still be manageable.

[Coding Enthusiast]

I'm trying to recover JBRai's private key with 49 out of 52 characters known. I've installed The FinderOuter (in a VM), but it asks for the locations of the missing characters.
Any chance you can add a loop to search all possible locations for the 3 missing characters? That is, assuming the rest of JBRai's key is correct.

I've tested it with a known key: it takes about 2 seconds to find 3 missing characters. To do the same on 3 unknown locations would take about 58^3 times longer, which means several days, but it'll still be manageable.

I'm not a math expert but I think it should take 20,825 times longer (58³=195,112)*. There is also the fact that the underlying algorithm will also be different that lacks most of the pre-computation that the current algorithm for known missing places has so it will be slightly slower. However, as I said before I have no idea how to generalize this so I hardcoded the heck out of it (only for this special case: missing 3 chars, probably will add a couple more smaller cases later), the benefit of it is that I know how to run it in parallel so the more threads your CPU has the faster it would run and I don't think 4 billion is going to take that long to finish.

* The problem with not knowing the missing places is that you'll have to first select different locations then loop through the 58 possible characters and keys are long (52/51 characters) so things get out of hand quickly. Example:

Code:

1 missing char (assuming compressed key):
  known location   -> 58              =            58
  unknown location -> 51*58           =         2,958
2 missing chars
  known location   -> 58*58           =         3,364
  unknown location -> 1,275*58*58     =     4,289,100
3 missing chars
  known location   -> 58*58*58        =       195,112
  unknown location -> 20,825*58*58*58 = 4,063,207,400

20,825 in last example (like others) is calculated using combination in mathematics which is n!/[k!(n-k)!] where n is 51 for compressed keys (52 char long with first one fixed to K or L) and k is 3 (the 3 missing places).

https://github.com/Coding-Enthusiast/FinderOuter/commit/73e8596993cdf68be49a4f20ba52afa2b1c1a5b1
Here is a preview, will publish a released version soon (the checkbox needs to be selected to enable this "special" case):

[Coding Enthusiast]

Version 0.1.1 is released.
https://github.com/Coding-Enthusiast/FinderOuter/releases/tag/v0.1.1.0
See changelog for more information.
Most notable changes are:
- A new feature for a special case where a compressed private key has 3 missing characters at unknown locations.
- Some small optimizations, bug fixes and improvements.

Future ideas (as soon as I publish my Bitcoin.Net library):
- Recovering mini private keys with missing characters (eg. a damaged physical coin)
- Converting versioned private keys (BIP-178 and a couple of Electrum versions) to normal keys
- Finding BIP-32 paths by only having the mnemonic/xkeys and a single child address/key

[LoyceV]

Version 0.1.1 is released.
https://github.com/Coding-Enthusiast/FinderOuter/releases/tag/v0.1.1.0

Thanks for the improvements! It's currently running, I expect it to take around 18 hours. I didn't give the VM full CPU access (80% of 2 CPUs) so it shouldn't bother me too much.

I don't have high hopes though: I tested all possible combinations of JBRai's private key with 54 characters, and none of them lead to a valid private key. I've seen what he wrote down, and apart from too many or not enough characters, he also has terrible handwriting, which makes it likely there are more mistakes.
If this doesn't produce any result, I'll stop trying. It's not the first time I've seen someone lose access to funds because of bad hand writing. And that's why I always try to recover anything before funding a key: test your backups!

Update: After 4.5 hours, it produced a private key! But the key is invalid, so something must have gone wrong in checking the key.

[iluvbitcoins]

Why do all of these bruteforce things run on Linux/Ubuntu?  
Only btcrecover is for Windows  
Dunno if it's better to run this on a VM Linux or use btcrecover on Windows?
I have an integrated GPU :S

[LoyceV]

Why do all of these bruteforce things run on Linux/Ubuntu?  

Lol, I actually had to install a bunch of Microsoft tools to run it, so I guess it works on Windows too.

[Coding Enthusiast]

Why do all of these bruteforce things run on Linux/Ubuntu? 

FinderOuter can run on any operating system. You just have to compile it yourself if you want to run it on Windows since I've only released the compiled version for 64-bit Linux OS. I can release more compiled versions if there is an overwhelming demand for it but security-wise it is best if you run it on a clean Linux specially if you are a windows user and want to use the same OS you use daily and may already be infected without you even knowing it.

Why do all of these bruteforce things run on Linux/Ubuntu? 

Lol, I actually had to install a bunch of Microsoft tools to run it, so I guess it works on Windows too.

hmm. Did you use the released zip file under "releases" and run it on Linux or did you compile it yourself? Because I can see you needing to install extra stuff for compiling (SDKs, Nuget packages,...) but there is no need to download anything else if you run the compiled version since it is self contained meaning even the framework (.net core) is included.

[LoyceV]

hmm. Did you use the released zip file under "releases" and run it on Linux or did you compile it yourself? Because I can see you needing to install extra stuff for compiling (SDKs, Nuget packages,...) but there is no need to download anything else if you run the compiled version since it is self contained meaning even the framework (.net core) is included.

I did not know that! As a Linux user, I picked the only tar.gz available, and didn't look at the zip. That indeed gave me the source code, and I followed instructions there.

[Coding Enthusiast]

I did not know that! As a Linux user, I picked the only tar.gz available, and didn't look at the zip. That indeed gave me the source code, and I followed instructions there.

It is GitHub that automatically adds the repository's source code as both a zip file and a tarball whenever a new release is published there (both named Source code) so that the source code at that exact commit is always available under the same binaries.
In any case, thanks for the report. I've added a short explanation to the ReadMe file that can hopefully prevent similar future confusions.

[LoyceV]

Update: After 4.5 hours, it produced a private key! But the key is invalid, so something must have gone wrong in checking the key.

Any idea why this could have happened?

[Coding Enthusiast]

Update: After 4.5 hours, it produced a private key! But the key is invalid, so something must have gone wrong in checking the key.

Any idea why this could have happened?

Do you know the reason for the key being invalid (for example is it the checksum, invalid character or out of range value)? Or is it just producing a different address? (You could use bitaddress.org for decoding, it will tell you the reason).

[LoyceV]

Do you know the reason for the key being invalid (for example is it the checksum, invalid character or out of range value)? Or is it just producing a different address? (You could use bitaddress.org for decoding, it will tell you the reason).

I tried Electrum and Mycelium, both didn't tell me the reason. I didn't use bitaddress because I couldn't run it offline at that moment. I guess the checksum must have failed.
The resulting key was the original, with 2 characters added at one place, and further one 1 character added. I was very hopeful at that moment that it would have found the the correct key.