# Identity and login

There is no account. There is a keypair on your device, and everything you do is signed with it.

## Keys, not accounts

A Nostr identity is a secp256k1 keypair. The public key identifies you; the private key signs what you send. There is no registration step because there is nothing to register with — the key is generated locally and is valid the moment it exists.

Two encodings you will see:

| Form | What it is | Sharing it |
| --- | --- | --- |
| `npub1…` | Your public key | Safe. It is your address. |
| `nsec1…` | Your private key | Never. It *is* you. |
| `nympq1…` | Your post-quantum code | Never. It opens your [quantum-resistant messages](https://nymchat.app/docs/post-quantum/). |

Your **nym** is the display name you chose plus four hex characters taken from your public key — `SatoshiFan#a1b2`. Names are not reserved and two people can pick the same one; the suffix is what tells them apart, and it cannot be borrowed without the key behind it.

> **There is no reset**
>
> Nobody holds a copy of your private key, so nobody can restore it. Lose it and the identity is gone: not locked, gone. If an identity matters to you, copy its `nsec` into a password manager now — and its `nympq` code beside it. The `nsec` alone cannot rebuild the post-quantum code, which is the whole point of it being separate, so the two are backed up together or not at all.

## Ephemeral identities

Sign up on the welcome screen and Nymchat mints a keypair for you on the spot. What happens to it next is a setting — *Generate Random Keypair Per Session*, under Settings › Privacy & Security:

| Mode | Behavior |
| --- | --- |
| **Disabled** *(default)* | The keypair persists across reloads, so your nym survives closing the tab and coming back. |
| **Enabled** | A brand-new identity every session. Nothing links this session to the last one. |
| **Hardcore** | A new keypair for *every message sent*. |

> **Hardcore mode breaks conversations**
>
> Nobody can reply to a pubkey that no longer exists. Private messages and group chats do not work reliably in hardcore mode, and settings will not sync. It is for shouting into a public channel and nothing else. Per-session mode has the same effect on settings sync, for the same reason.

There is also *Auto Ephemeral Mode on Restart* under Settings › Messaging & Display, which skips the welcome screen entirely and drops you straight into a fresh ephemeral session.

> **What an ephemeral nym does and does not hide**
>
> It hides *you* from other users: there is no name, email or phone number behind the key. It does **not** hide your IP address from the relays you connect to. Nymchat routes relay traffic through its own proxy by default, which keeps your address off third-party relays — see [the privacy proxy](https://nymchat.app/docs/relays/#the-proxy) — but if that matters to you, use Tor or a VPN as well.

## Logging in with a Nostr account

The Login tab takes an identity you already have. Four ways in, in descending order of how much your key is exposed:

![The Nymchat login screen offering a browser extension, a remote signer, a bunker string, or pasting an nsec.](https://nymchat.app/images/docs/login.webp)

*The login tab. Extension and remote signer never hand the key to the app.*

| Method | Where the key lives | Needs |
| --- | --- | --- |
| **Browser extension** (NIP-07) | In the extension. Nymchat asks it to sign and never sees the key. | Alby, nos2x or similar |
| **Remote signer** (NIP-46) | On another device or service. Signing requests go to it. | Amber, nsecbunker, nsec.app |
| **Bunker string** | Same as above — paste a `bunker://` URI instead of scanning. | A signer that emits one |
| **Paste an nsec** | In this browser's or app's local storage. | Nothing |

Prefer an extension or a remote signer where you can. If you paste an `nsec`, turn on [identity encryption](https://nymchat.app/docs/security/#identity-encryption) so the stored key is not readable from the device.

A persistent identity gets you a nym that survives restarts, a profile other clients can see, settings that follow you between devices, and zaps that can actually be paid to you.

## Your profile

Tap the "Your Nym" panel at the top of the sidebar to edit:

- **Nickname** — up to 20 characters. `/nick` does the same thing from the composer.
- **Avatar** and **banner** images.
- **Bio** — up to 150 characters.
- **Bitcoin Lightning address** — where [zaps you receive](https://nymchat.app/docs/lightning/#receiving) are paid.
- **Reveal this nym's private key** — a collapsed section that shows the `nsec` so you can back it up.

![The Nymchat nym editor, with fields for a nickname, avatar, banner, bio and Lightning address.](https://nymchat.app/images/docs/nym-editor.webp)

*The nym editor, reached by tapping the “Your Nym” panel.*

For a logged-in Nostr identity this is your ordinary Nostr profile (a `kind 0` metadata event), so a change here shows up in every other Nostr client too.

> **Careful**
>
> Press and hold that same panel for two seconds and Nymchat wipes itself from the device immediately, without asking. See [Panic wipe](https://nymchat.app/docs/security/#panic-wipe).