Father lost his Electrum wallet, and remembers some of the words in the seed

[ileikmath]

So if the wallet is big enough its worth it. If you are missing 4 or 3 words or less, then its a piece of cake.

Yayy hope. I'll try getting something setup for those cases, and otherwise, this is sort of the safest to hodl I suppose.

Its a custom c code, no python github lib repo...

May I see some of you code? Or can you point me a direction to make something similar? I'm comfortable with programming in C and the math surrounding cryptography, but I've never taken a course in it, and wouldn't know where to start for deriving an electrum wallet as opposed to a standard BIP39 wallet

[HCP]

if you have 7 out of 12 words, it will take approximately 1 year on a 10x 1080TI rig to find the missing five (from own experience)

Does that require that you know the correct order of those 7 words? Or does it not matter?

[pooya87]

OpenCL benchmarks show that a single 1080 Ti has a Geekbench score of 60898. (https://browser.geekbench.com/opencl-benchmarks) It says that a Core i3-8100 running the same tests would get a score of 1000, so however long the key searching operations take on that Core i3, are about 60.898x faster on a 1080 Ti.

benchmarking is a very complicated process that can easily be wrong if you take the wrong steps. i couldn't figure out the exact things they measure and there is no source code, but it appears that they are benchmarking basic things (playing a video, opening your browser, playing a game,...). these could be different from computing hashes. for instance some CPUs have phenomenal performance in computing SHA256 since they have intrinsics and the process could be easily parallelized which would take a lot faster on CPU and even though GPU speed is still faster but it will no longer be 60x faster.

[ileikmath]

these could be different from computing hashes. for instance some CPUs have phenomenal performance in computing SHA256 since they have intrinsics and the process could be easily parallelized which would take a lot faster on CPU and even though GPU speed is still faster but it will no longer be 60x faster.

Correct me if i'm wrong please, but shouldn't the GPU still see a large speedup because this task is easily parallelized? Or am I missing something about the capabilities of the few thousand cuda cores

[pooya87]

these could be different from computing hashes. for instance some CPUs have phenomenal performance in computing SHA256 since they have intrinsics and the process could be easily parallelized which would take a lot faster on CPU and even though GPU speed is still faster but it will no longer be 60x faster.

Correct me if i'm wrong please, but shouldn't the GPU still see a large speedup because this task is easily parallelized? Or am I missing something about the capabilities of the few thousand cuda cores

you are correct, GPU is a lot faster and i've already mentioned this in my comment. my point was that it may not be 60x faster that is reported by that site since what they are benchmarking is not the specialized hash computation required to brute force mnemonics.

[NotATether]

benchmarking is a very complicated process that can easily be wrong if you take the wrong steps. i couldn't figure out the exact things they measure and there is no source code, but it appears that they are benchmarking basic things (playing a video, opening your browser, playing a game,...). these could be different from computing hashes. for instance some CPUs have phenomenal performance in computing SHA256 since they have intrinsics and the process could be easily parallelized which would take a lot faster on CPU and even though GPU speed is still faster but it will no longer be 60x faster.

Yeah, it would be more accurate if btcrecover had a parameter for running it's own hashing benchmark per combination. I know VanitySearch also has such an option, and it shouldn't be too hard to implement. Just use a throwaway seed with a missing word and make a result in combinations/second.

[adaseb]

I also had this issue in the past where instead of writing it down, I decided to "remember" the seed. At first I would recite it every day, then I made a story out of it using all the 12 words. And from time to time I would basically do a test signature and verify or do some small transaction to keep it in my memory. However...

Then Nov 2018 happened, BTC dropped to like $3K and decided to not sell my BTC in that wallet for like almost a year. Then when it went up in June 2019, I tried to access the wallet and could only remember 6 of the words, in the correct order. I figured I would just look at the dictionary and the words that I am missing would appear and I would be set. However you don't realise how many words there are and you will second guess yourself assuming you know the word when its not the correct word.

Basically in the end. Out of the blue for some reason months and months later, I "finally" remembed the missing 6 words. Tried it on Electrum and the wallet finally opened. Basically the word that I "thought" were correct weren't even close to being correct.

Hence... don't use your brain as your only source of your seed unless you use this seed everyday.

[o_e_l_e_o]

Hence... don't use your brain as your only source of your seed unless you use this seed everyday.

I would go further and say don't use your brain as your only source of back up, full stop. Even if you are using the seed phrase every single day, there are literally thousands of things that can happen to you without any warning that can impact your memory. A simple fall or trip and a blow to your head. Road traffic accidents, work place accidents, accidents at home, etc. 70 million people suffer from a traumatic brain injury each year. 1 in 6 people will have a stroke at some point in their life. Severe infections (COVID included) can leave you with neurological and memory issues. There are brain aneurysms. And seizures. And dementia. And Alzheimer's. And the list goes on.

Yes, it is cool to be able to remember a seed phrase and have instant access to your bitcoin from anywhere in the world without having to carry a wallet with you. But you should always have that seed phrase physically backed up on paper somewhere safe as well.

[Lucius]

Yes, it is cool to be able to remember a seed phrase and have instant access to your bitcoin from anywhere in the world without having to carry a wallet with you. But you should always have that seed phrase physically backed up on paper somewhere safe as well.

It may be cool, but I still wouldn’t want to keep my seed in my brain - because there’s also a physical assault vector where the attacker can use some drugs that can be used as a truth serum - so although we often see it in movies, in some countries it is still used when interrogation of suspects. Some people even under the influence of alcohol or marijuana say a lot of things they would never say in a conscious state - and in my country we have a saying that says "a drunkard says what a sober man thinks".

[o_e_l_e_o]

It may be cool, but I still wouldn’t want to keep my seed in my brain - because there’s also a physical assault vector where the attacker can use some drugs that can be used as a truth serum - so although we often see it in movies, in some countries it is still used when interrogation of suspects.

Truth serum doesn't actually exist - it is just hollywood nonsense, which is why "confessions" under the influence of it (whatever particular substance "it" is - several have been used) are not accepted in court. In reality all you are doing is sedating the subject and making them suggestible, and many will agree to whatever you tell them. I would imagine they are next to useless when it comes to extracting individual words. And regardless, if someone can perform a $5 wrench attack or similar to make you spill your seed phrase, then they can do exactly the same to make you spill your password for your software wallet, the location and PIN of your hardware wallet, the location of your back up, etc. Not remembering your seed phrase is not a protection against such an attack. You need to use plausible deniability instead, such as secondary wallets, passphrases, etc.

Some people even under the influence of alcohol or marijuana say a lot of things they would never say in a conscious state - and in my country we have a saying that says "a drunkard says what a sober man thinks".

All the more reason not to become so intoxicated that you lose your senses.

[adaseb]

Getting drunk and screaming out your private seeds at the top of a building is most likely not going to happen. People under the influence don't do things they normally wouldn't do, it just makes them do things they are normally scared to do, like walking up and talking to some girl.

But keep in mind that if someone is physically there with you, there are ways they can easily get the private keys out of you. I don't think most thieves would go thru the trouble of truth serum or try and get your drunk. This is why you should keep it to yourself if you are a bitcoin investor. Because if you drive around with a BTC sticker on your Ferrari then don't be surprised if one day you get jumped.