Ah, the private key, the single point of failure that will lead to heartbreak for many a Bitcoiner or nostr user who fails to guard their seed phrase, a painful reminder of what it means to take personal responsibility over your funds or your data.
Both Bitcoin and nostr use private and public key pairs; with Bitcoin, you use it to control and access your wallet and funds, and with nostr, you use it to control and access your account and related content hosted on relays.
While they have similar roots, nostr and Bitcoin have different user experiences and goals. When you use Bitcoin, it’s best practice to use a private key to generate multiple public keys since you want to maintain privacy as much as possible and limit data connections between any single public address.
While with nostr, one nsec to one npub is the better approach since you want to build a reputation on one public key.
Managing your nostr keys is a little different from your Bitcoin keys, securing your digital identity is paramount in the evolving landscape of decentralised communication.
Just like with Bitcoin, if you lose or expose your private key on nostr, that’s it; you’re cooked!
Kiss those funds goodbye, or kiss that account goodbye.
Use of Keys and its Risk Factor
Securing your Nostr keys is a bit more tricky than Bitcoin since you want to use it to engage with apps and clients constantly.
You need a copy of your keys hosted on an internet-connected device.
Thankfully, browser extensions like Nos2x and Alby can handle the nostr key storage for you, but they won’t be much help to you if your PC crashes.
So you’ll need to keep a copy around.
Treat your private key much better than a highly sensitive password.
Don’t go save it on some cloud note app, screenshot it on your computer, or use some online password manager.
At the very least, keep a hard copy offline, use a nostr signing device to keep a copy of your keys, or use a locally hosted password management tool that you can run on your Bitcoin node in a box like Umbrel or any personal server setup you prefer.
What is Frost?
Frostr is a t-of-n remote signing and key rotation protocol designed explicitly for the Nostr ecosystem.
It’s a security solution that allows Nostr users to distribute the power to sign messages across multiple devices or parties, requiring only a threshold number of them to complete a signature.
The name “Frost” cleverly combines elements of its foundation:
- It’s built for Nostr (Notes and Other Stuff Transmitted by Relays)
- It’s powered by FROST (Flexible Round-Optimized Schnorr Threshold signatures)
The protocol uses FROST in order to coordinate the signing of a message between multiple signing devices owned by a single user.
- Website or application makes a request to the user’s signing device (to sign a note).
- User’s device makes a signed request to the remote signing device(s).
- Each remote device verifies the request, then responds with a partial signature.
- User’s device verifies each partial signature, then adds their own.
- The signatures are combined, and the complete signature is returned to the website/app.
How Does Frostr Work?
At its core, Frostr implements a threshold signature scheme. Here’s what that means:
- Distribution of Key Shares: Instead of having your private key exist in just one place (creating a single point of failure), Frostr splits it into multiple shares.
- Threshold Requirements: You set a threshold (the “t” in t-of-n) of how many shares (out of the total “n” shares) must participate to create a valid signature.
- Collaborative Signing: When you need to sign a Nostr message, the required number of key share holders collaborate to produce a signature without ever reconstructing the complete private key.
- Key Rotation: Frostr allows you to update key shares periodically without changing your public identity on Nostr, enhancing long-term security.
Why Frostr Matters for Nostr Users
Nostr is a protocol for censorship-resistant social media and communication. Still, to maintain this promise, it relies on users to be able to manage private and public key pairs, something that doesn’t come naturally to the average internet user.
If you think of a social media service like Facebook, they handle millions of password or account recovery requests every day because people can’t be bothered to manage their account access.
With nostr, there is no central authority to help you out; if you dox your keys or paste your nsec malicious client, you’re on your own. Your Nostr identity is tied to your cryptographic key pair, making key management critically important.
Given the fact that private and public key signing can be unforgiving to mistakes, adding ways to reduce your keys’ exposure is a plus as we take one baby step closer to the normie-sation of nostr.
Frostr addresses several key challenges:
Enhanced Security
With traditional key management, losing your device means losing your Nostr identity. With Frostr, even if one or more devices are compromised, your identity remains secure as long as the attacker doesn’t control enough shares to meet the threshold.
Practical Key Management
Want to use Nostr across multiple devices without compromising security? Frostr allows you to distribute key shares across your laptop, phone, and tablet, requiring any two to sign messages, giving you a little more breathing room to stuff up or take risks.
If nostr is to roll out to the wider internet with services like nostr auth, where users can sign into any site with their nostr keys, having a failsafe like this will be a life saver for many account holders.
Team Accounts
For organisations or projects with shared Nostr accounts, Frostr enables proper access control. For example, a 3-of-5 scheme ensures no single team member can post without others’ participation, which means less chance of your brand account getting jacked and used to shill a meme coin.
Here’s looking at you Twitter!
Recoverability
If you lose one device, your Nostr identity isn’t lost with it.
You can still sign using your remaining devices and eventually rotate to a new key setup.
Technical Foundation: FROST
Frostr’s security is built on FROST (Flexible Round-Optimized Schnorr Threshold signatures). FROST is a cryptographic protocol that enables efficient threshold Schnorr signatures, which are compatible with Nostr’s signature scheme.
The advantage of FROST over other threshold schemes is its efficiency – signature generation requires minimal interaction between participants, making it practical for everyday use in applications like Nostr clients.
Getting Started with Frostr
To implement Frostr for your Nostr identity:
- Decide on your security model (how many shares and what threshold)
- Generate your distributed key shares
- Distribute these shares to your devices/trusted parties
- Configure your Nostr clients to use Frostr for signing
The Future of Key Management in Nostr
As the Nostr ecosystem grows, secure and flexible key management solutions like Frostr will become increasingly important. By separating identity from individual devices, Frostr and similar protocols pave the way for more resilient digital presence in decentralised networks.
Frost represents another step toward making decentralised protocols like Nostr not just technically sound but also practical for everyday users who shouldn’t need to become cryptography experts to maintain their digital identity securely.
Note: Before you dive in, remember Frostr is still under active development, with all the project’s open-source code available to review and try out. Contributors, testers, and reviewers are welcome to test it, poke holes, and provide feedback.
So, you shouldn’t use your OG or daily NSEC with this software.
Instead, spin up a new one for testing instead; it won’t cost you anything!
Anyhooz, Happy note and other stuffing!
Do your own research.
If you want to learn more about Frostr, use this article as a starting point. Don’t trust what we say as the final word. Take the time to research other sources, and you can start by checking out the resources below.
