Pertaining to current occasions (each the FTX collapse and LastPass hack), self-custody of your crypto and with it secure backup of your mnemonic seed phrases has by no means been extra warranted I feel. I maintain my seed phrases secured in an area KeePass database in a couple of completely different locations, however this man stored them on LastPass. I wrote this script a couple of years in the past to have the ability to securely write them down in a straightforward human-readable format and never have to fret about it even when a thief/hacker got here throughout them: https://github.com/mifunetoshiro/Seedshift
It steganographically encrypts your English mnemonic seed phrases utilizing a date shift cipher, and optionally obfuscates them by mapping them to the Unicode characters within the Conventional Chinese language BIP-39 wordlist. There’s additionally an possibility to separate the encrypted/obfuscated seed phrases into 2-out-of-3 restoration sheets.
Observe that you do not want this script to encrypt/decrypt your seed phrases with a date shift cipher, you are able to do all of it by hand on a bit of paper. Please learn the “Secure utilization” part on GitHub!
Instance utilization:
For instance oppose duck whats up neglect reveal key humor mosquito highway evoke flock hedgehog are your seed phrases. The script takes dates in YYYY-MM-DD format. So as an instance you employ 3 dates: your mom’s birthday is 1963-07-10, your father’s birthday is 1956-04-27, and your birthday is 1994-01-31. The script will robotically kind the dates from oldest to latest (you do not have to enter them in that order) and cut up every in 3 elements (yr, month, day) which will likely be used to right-shift the phrases’ positions within the English BIP-39 wordlist. Within the above instance: 1956, 4, 27, 1963, 7, 10, 1994, 1, 31. The script will shift the phrases and output a desk with the shifted phrases, their quantity and the Unicode codepoint of the Chinese language counterpart character within the Conventional Chinese language wordlist (if current):
| # | Authentic | Quantity | Shifted | Encrypted | Quantity | Chinese language |
|----|----------|--------|---------|-----------|--------|---------|
| 1 | oppose | 1245 | 1956 | mosquito | 1153 | 5BF6 |
| 2 | duck | 543 | 4 | mud | 547 | 5B57 |
| 3 | whats up | 855 | 27 | lodge | 882 | 6162 |
| 4 | neglect | 1185 | 1963 | most | 1100 | 7238 |
| 5 | reveal | 1476 | 7 | wealthy | 1483 | 6C2E |
| 6 | key | 977 | 10 | kitten | 987 | 6FC3 |
| 7 | humor | 889 | 1994 | hair | 835 | 4E4E |
| 8 | mosquito | 1153 | 1 | mom | 1154 | 5348 |
| 9 | highway | 1496 | 31 | salute | 1527 | 95CA |
| 10 | evoke | 625 | 1956 | dream | 533 | 52E2 |
| 11 | flock | 715 | 4 | flush | 719 | 932F |
| 12 | hedgehog | 853 | 27 | hospital | 880 | 4E95 |
To decrypt them and get again your authentic seed phrases, the script will settle for the encrypted phrases, their numbers or the Unicode codepoints and the identical dates you used to encrypt them (once more, you may also do all of this by hand and do not want the script in any respect).
Observe that the final encrypted phrase will almost definitely not be a sound checksum phrase (within the above instance, hospital is legitimate, although). Having a sound checksum final phrase can present believable deniability in that the encrypted phrases are in reality encrypted, as they’re legitimate BIP-39 seed phrases. You can even retailer a small quantity of cash there, so if somebody ever steals/makes use of your seed phrases, that is all they’ll assume you could have. The script can generate a sound final checksum phrase in your encrypted phrases if you wish to change it (if it is already legitimate, the script will inform you so, and you do not have to switch it). In case you select to switch it, you’ll have to keep in mind or write down your authentic or encrypted final phrase as properly, or you’ll optionally must bruteforce/generate all legitimate checksum phrases with this script and take a look at them one after the other (there are 128, 64, 32 and eight legitimate checksum phrases for 12, 15, 18 and 24 seed phrases, respectively)!
You may retailer the Chinese language Unicode codepoints in a number of methods, since every is 4 characters lengthy (simply keep in mind this reality whenever you wish to rebuild your authentic seed phrases). You can write it unchanged: 5BF6 5B57 6162 7238 6C2E 6FC3 4E4E 5348 95CA 52E2 932F 4E95, or, to make it look much more random, as a bunch of hexadecimal characters that return ineffective nonsense when transformed again to textual content ([ö[Wabr8l.oÃNNSHÊRâ/N), you could write it without spaces: 5BF65B57616272386C2E6FC34E4E534895CA52E2932F4E95, you could write it with a space every 2 characters: 5B F6 5B 57 61 62 72 38 6C 2E 6F C3 4E 4E 53 48 95 CA 52 E2 93 2F 4E 95, you could group two or more together: 5BF65B57 61627238 6C2E6FC3 4E4E5348 95CA52E2 932F4E95, etc. I included “mapping_table.txt” and “mapping_table_unicode_sorted.txt” files for manually looking up and converting the Unicode codepoints.
Optionally, the script can output a 2-out-of-3 recovery sheets like this:
| Sheet 1 | Sheet 2 | Sheet 3 |
|----------------------------|----------------------------|----------------------------|
| #1: mosquito / 1153 / 5BF6 | #1: mosquito / 1153 / 5BF6 | #2: dust / 547 / 5B57 |
| #2: dust / 547 / 5B57 | #3: hotel / 882 / 6162 | #3: hotel / 882 / 6162 |
| #4: maximum / 1100 / 7238 | #4: maximum / 1100 / 7238 | #5: rich / 1483 / 6C2E |
| #5: rich / 1483 / 6C2E | #6: kitten / 987 / 6FC3 | #6: kitten / 987 / 6FC3 |
| #7: hair / 835 / 4E4E | #7: hair / 835 / 4E4E | #8: mother / 1154 / 5348 |
| #8: mother / 1154 / 5348 | #9: salute / 1527 / 95CA | #9: salute / 1527 / 95CA |
| #10: dream / 533 / 52E2 | #10: dream / 533 / 52E2 | #11: flush / 719 / 932F |
| #11: flush / 719 / 932F | #12: hospital / 880 / 4E95 | #12: hospital / 880 / 4E95 |
Write down and store each sheet separately at a different location.
