How a mnemonic seed with offset passphrase works in Monerujo

Monero seeds explained

In case you don’t know what a seed is, the seed is that list of 25 random words that Monerujo shows you when you create a wallet, and that’s the moment you should write it down, and keep it safe (so you don’t lose it) and secret (so you’re the only one who knows it).

A Monero seed is born
Just like in Jurassic Park

Offset passphrases explained

By now, we know that the seed is a list of 25 words that represents the DNA of your wallet. What would happen if we add a 26th word to the key, and run the converter again?

Original key + “ruth” = CryptSeed!

Ok but… why? How’s that useful?

Usefulness never stopped a nerd! Now seriously, the main utility for such a thing is to avoid the evil maid attack. With this feature, when you can create a wallet with a seed offset phrase, you can write down the original seed in one place, and the offset passphrase in another, or just remember it (you chose it yourself after all). Store the seed somewhere, and if someone else finds it and tries to restore your wallet to steal your moneroj, all they’ll find is an empty wallet.

The evil maid restoring a deceptively meager XMR wallet.

Words of caution

“Being your own bank” entails not only the fun parts, also taking care of your backup, secrecy, and security protocols. If you forget or lose your offset passphrase, your seed alone won’t be enough to recover your funds. And you lose access to them. Forever. If you plan to use this, please be sure you understand it. Test it. Send some tiny funds, delete the wallet, restore it and check that everything is there. Make yourself familiar with the procedure.



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Co-Founder at Sloop + Monerujo team member