Autocrypt Secret Key Backup

This is for Autocrypt Level 1 or later…

The MUA generates a strong “backup code” and gets the user to write it down somewhere. Then it serializes its secret key material into a message encrypted by the the backup code. This message is given a custom header and is sent to the account in question:

Autocrypt-Secret-Key-Backup: key_backup_data=<encrypted_secret_key>


should the MUA store the message in the SMA, or store it to file or what?



Fill in here

Prompting the user for backup code?

Note also that the backup code MUST be strong – it is subject to brute force attacks by anyone who holds a copy.

Backup and Sync


say something about the relationship between backup and sync