Take a book. Any book you like.
Find all the words your mnemonic phrase contains.
Mark their location using page-paragraph-word number combination, ie 120826 would mean page 12, paragraph 8, word 26.
As a result you will have a series of 6 digit numbers which you are free to store on your Google drive, email to yourself or paint on your roof
Without knowing what the key book is no one will be able to decipher it.
Find all the words your mnemonic phrase contains.
Mark their location using page-paragraph-word number combination, ie 120826 would mean page 12, paragraph 8, word 26.
As a result you will have a series of 6 digit numbers which you are free to store on your Google drive, email to yourself or paint on your roof
Without knowing what the key book is no one will be able to decipher it.This may sound like a idiot-proof concept, but is in reality relatively vulnerable.
If someone gains access to your google drive (or to your roof
) and knows the system you have used to substitute your words, it just takes a few minutes to hours to test all books which might have been used.Anyone in your locality who might be able to guess what you are into, is able to check the words from a few thousand books similar to what you are interested in.
While this might work out if you hide all possible information (Substitution, book used, etc.. ), Security by obscurity is a bad approach.