password = sha256(service + username + master_password)
# Where -
# service: TLD of the website/service or something unique in case of a mobile app
# username: User's email id or username on that particular service/app
# master_password: A super secure password (and the only one) which the user will have to remember. Something like: "C0rrectCab@lloB@tterySt@p1e"