# Email Flow In creating an email flow that maintains PRIVACY and SECURITY whilst also being convenient to use, the following principles were observed: - Keypair must be generated client-side - Keypair must be protected by a long and complex password - It must be possible to change the password - It must remain possible to work offline - Network traffic must not contain identifying metadata All of the above is achieved using a high level signup flow as follows: 1. User provides email and complex password 2. These are used to encrypt a locally generated keypair into a backup 3. Email address, Public Key and encrypted backup are sent to the server 4. Account is validated The password is only used to encrypt/decrypt the local backup and is never stored or sent anywhere. When perforing a login, the flow is: 1. Generate a temporary key pair for secure server communication 2. Validate the email 3. Provide the encrypted keypair for the user to unlock All key signing / encryption operations happen on client side using [private class properties](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes/Private_properties). ## SIGNUP FLOW ```mermaid sequenceDiagram autoNumber actor U as SIGit User participant W as SIGit Website participant D as Server Participant DB Note over W,D: All comms encrypted with throwaway
(ephemeral) client keys and a
.well-known server key U->>W: Click SIGNUP U->>W: Provide Email and Complex Password Note over W: Validate Email
Ensure Complex Password
(Min 21 chars) Note right of U: User is warned that they CANNOT
RESET PASSWORD, should USE
PASSWORD MANAGER etc Note over W: Nostr Keypair Generated
& Encrypted inside a
PRIVATE method,
with COMPLEX password.
Password variable is not
stored, sent or printed
anywhere.
Any sensitive variables
are immediately destroyed. W->>D: Request account activation Note right of W: Event uses PoW and
encrypts PUBKEY, EMAIL,
and the encrypted BACKUP
to the dvm@sigit.io pubkey
using the ephemeral key Note over D: Verify PoW,
event.created_at,
event.id D -x DB: Check if email exists Note over D: If email already exists, and
user.last_seen <> null then
send user to LOGIN.

If email exists and last_seen
is null, then DELETE the
current entry.

Otherwise#58; D->>DB: Create DB entries Note over DB: USER insert#58;
#128274;user.id=uid()
user.pubkey=lowcase($PUBKEY)
user.email=lowcase($EMAIL)
user.last_seen=null
user.created_at=now()
user.bkp=$BACKUP Note over DB: SESSION insert#58;
#128274;session.pubkey="ephemeral pubkey"
session.email_code=INT (6 digits)
session.user_id=user.id
session.created_at=now() D->>U: Send session.email_code via email D->>W: Account created Note left of D: Payload is the user.id and/or
an encrypted (and detailed)
error message Note over W: Verify DVM pubkey,
event.created_at,
event.id W->>U: Tell user to check email and
to open it in the
SAME BROWSER SESSION Note over W: Screen to accept the 6 digits
is already displayed
(mobile optimised if relevant) U->>W: User opens link or enters the code W->>D: Verify Account Note right of W: Event uses PoW and
encrypts both user_id
and email_code
to DVM pubkey D -x DB: Check email_code where
session pk=event pk D->>DB: If email_code matches,
update USER table where
session.user_id=user.id Note over DB: USER update#58;
user.last_seen=now() D->>W: Account activated Note left of D: Payload is an empty string or
an encrypted (and detailed)
error message Note over W: Verify DVM pubkey,
event.created_at,
event.id W->>U: User is automatically logged in Note over W: Ephemeral key is destroyed
Default relay list is broadcast
using the user pubkey ```