Did any 2009 Bitcoin service generate multi-word passphrases?

External question — Bitcoin Stack Exchange Author: Paddy Original post: https://bitcoin.stackexchange.com/questions/131098 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. I am trying to identify a Bitcoin-related service or wallet that I remember using around 2009. I understand that modern mnemonic recovery seeds (such as BIP39) did not exist in 2009, and I am not claiming that this was a modern seed phrase. My recollection is the following: I was introduced to Bitcoin by a friend. I created a new email account specifically for this. I registered on a website with an email address and password. I bought Bitcoin for a small amount of euros. My recollection is that payment was made by bank transfer from a German bank account. Afterward I could see a Bitcoin balance associated with my account on the website. I was advised to move the bitcoins to a wallet so that I would still have access to them if the website disappeared. I did not install wallet software. I remember doing this in the browser. During this process, the system generated a number of apparently random words for me. I understood these words at the time as a password/passphrase and wrote them down on paper. I kept that piece of paper for many years. I no longer know the exact number of words, so I do not want to claim that it was 12, 16, 24, etc. There is one additional unusual memory: while using the words, I remember seeing an extremely long, apparently random sequence of characters in the browser's address bar. I cannot reliably reconstruct what it contained or what technical mechanism produced it. I also remember the website/interface as having a dark or black background, but I consider that visual memory less reliable than the other details. I am aware that parts of this description do not fit the commonly documented history of Bitcoin wallets and exchanges. That discrepancy is exactly what I am trying to investigate. Possible explanations I am considering include an experimental service, a non-standard key-generation scheme, a service that was not actually a Bitcoin wallet, a later event being incorrectly dated in my memory, or even a fraudulent service. I am particularly interested in contemporaneous evidence: archived websites, source code, mailing-list posts, forum posts, screenshots, or documentation from 2009–2010. There is also an older question by user GPHM describing a remembered 12–16 word passphrase from early 2009: The BTC core wallet lets me choose my own passphrase with 12-16 words. The latest would be late January, early February 2009. What wallet was I using? I can't find a reference online. Everyone says that passphrases weren't used until 2013. I am trying to get my wallet back. I now remember my passphrase. I do not know GPHM and found that question only recently. I would be very interested in hearing from GPHM if they ever see this, but I do not want to assume that our experiences involved the same system. Does anyone know of a Bitcoin-related website, wallet prototype, key-generation tool or other service from 2009–2010 that could match any of these technical characteristics, particularly automatically generated words used as a password/passphrase?

External answer — Bitcoin Stack Exchange Author: Mathreed_ Original post: https://bitcoin.stackexchange.com/a/131099 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. I think the important thing here is to separate "multi-word passphrase", "mnemonic" and "BIP39 seed". They aren't necessarily the same thing. Bitcoin Core did not generate mnemonic phrases in 2009. The early Bitcoin client generated private keys and stored them in wallet.dat . Wallet encryption with a passphrase was added later, in Bitcoin 0.4.0 (September 2011). BIP39 is much later still, so if the date really is 2009, it cannot have been a BIP39 seed phrase. That said, I wouldn't conclude that a 2009 Bitcoin-related service could not have generated several English words. There were other possibilities. A website could have generated a password from a dictionary, used a proprietary mnemonic/recovery scheme, or simply used a multi-word passphrase as part of a brain-wallet-style system. Electrum is a good example of why the terminology matters. It had a 12-word seed system around 2011, before BIP39 existed, and its seed format was completely different from BIP39. Blockchain.info is another interesting case. Its early wallet system used recovery mnemonics, but these were also not BIP39 seeds. So I'd be cautious about statements like "Bitcoin didn't have passphrases until 2013". That's mixing together several different technologies. Bitcoin Core had encrypted wallets and passphrases by 2011, while proprietary mnemonic systems existed before BIP39. If the original recollection really is from 2009, the most interesting question is probably not "which Bitcoin seed format was used?" but rather "which early Bitcoin website could have generated a multi-word password/recovery phrase?" If there is also a screenshot, URL fragment, wallet file, or even a partial description of the website/interface, that could be much more useful for identifying the service.