Rejected pass phrase - how can you remedy the fail and regain access to your funds?

Pass phrase issues.

So you're trying to restore your wallet, but the passphrase you have written down is rejected. What is happening? What can you do about it?

Firstly you need to understand some things about your passphrase and then hopefully you will be able to resolve the issue and regain access to your wallet, without being tempted to make the fatal mistake of asking someone else to help.

More than once, I have seen someone share a photo of a handwritten pass phrase, asking others if they can help guess at what a poorly written word might be. Most of the time this is entirely unnecessary. because the words in a pass phrase are not a random selection of words at all.

Most pass phrases are using a standard called BIP39, the English list consists of 2048 words which have been carefully selected to ensure the first four letters in each word are unique - three letter words are also present, for these the first three letters will be repeated in longer words, for example we have: air and airport; and act, action, actor, actress and actual. These features make it far easier to solve an issue than you might imagine. the final word is a checksum.

Let's imagine you have the following word list

tender

focal

armed

canoe

math

beet

clay

pig

october

wool

tomorrow

patient

When you enter the list it fails to restore your wallet - what can you do?

Firstly you could enter your words, one at a time, into this BIP39 generator, and it will immediately suggest solutions, doing this reveals that tender should be render, focal should be local and beet should be beef.

If that fails you may have to get a bit more forensic, let's imagine you have a list including the word boney, you try the generator above and it suggests bone, which proves not to work - what now?

Let's manually check the words against the list of BIP39 words, if you do this you will straight away find boney is not a BIP39 word - however, it is also worth checking the end of a word in case the error is at the start, when you do this you find that honey is also a possibility.

Sometimes your list of 12 words is a seemingly valid list, but the pass phrase still does not work, what then?

Here, you need to check the list for valid words that may have alternative candidates, for example: wood is a valid word, but so is wool; fox might be fix; depending on handwriting you may even find that just is in fact junk.

More complex issues

If we have a torn, stained, defaced, or otherwise partially illegible list we may still be able to solve the issue by searching using the letters we can see. For example we have a pass phrase found while sorting our late grandfather's paperwork. The piece of paper it is written on has water damage and the top three words are only partly legible.

For the first three words we can see -

...pt

.....x

..ar..

The first word ends in pt - which gives us three candidate words, adapt, erupt and script.

The second word ends in x, here you have a few candidates - box, fix, fox, index, matrix, mix, relax, and six. Looking at the damaged word you can see it was not a three letter word, from this you are able to reduce the candidates to just three choices.

The third word is tougher, you can see it is a longer word, certainly not three or four letters long and there is clearly more than one letter each side of the ar - you make a list of all the words containing ar and eliminate the ones that do not meet these criteria. That leaves us with - charge, clarify, kangaroo, quarter, and search.

Head back to the generator and enter the various candidate lists, because the final word acts as a checksum only one list will prove to be valid. After some trial and error you determine the words to be erupt, relax and quarter and unlock your sadly departed grandfather's wallet to find he was sitting on 3 BTC

Sometimes a challenge may seem impossible, but even if words are missing entirely they can be found, particularly if the last word (checksum) is present. There are resources in github for calculating missing words, take care finding tools which are safe before entering partial lists, because even a partial list given to the wrong person can result in your funds vanishing.