I think a simple key isn’t enough to protect our data, so i would like to have an opt-in (ask validation to other synced brave) before start the real sync, like that even if someone find the key we are protected.
Now if someone find the key we are screwed.
Why no Username and Password login System? exactly what i think. Just a phrase!. Everyone can see that!! my passwords, my bookmarks
Because the world go passwordless (the password is a thing that must disapear (leaking and bruteforce vulnerable), so the encryption key + a simple validation is actually better security, than a username password + otp (can be phished)
syncchain is visible to all
They are in the crypto chain why not, if i have a control of who can rejoin my key it’s enough (since the person who try to connect, must have ok by one of my hardware before sync), better than a user/password that can be stolen by malware or so.
Edit : also less modification more fast it’s released.
you are not at your home. You have to use someone’s computer. How will you access your bookmarks and passwords for sites you don’t remember ?? nobody can remember sync phrases of every site.
she asking for adding extra security layer for example
some sites offer 2FA so you do not just relay on username and password but also a second way maybe sms (which is bad) or email or code sent to certain app
so she ask that in case of her key stolen no one can use it unless he/she provide a password or maybe any other authentication method
First i do not connect myself on a computer who is not mine (if it infected with malware goodbye your account.
Second i take my phone and have my bookmark on my pocket.
Exactly, the only reason i do not sync anything (only bookmark) it’s because a simple key without control of who can really use it isn’t enough for me sync other more sensitive info (history, password etc).
I agree but sometimes life happens (emergency situation)
yes but hope to see a validation at first and account after if they want 
Nobody Else want that ?