YOUR DIGITAL LIFE.
UNDER YOUR CONTROL.
Sideband brings identity, people, private messages, applications, payments and permissions into one simple system on the iPhone. Instead of every app owning a separate piece of you, the phone becomes the place where you decide who you are, what an app may do and when money may move.
WHAT IS SIDEBAND?
Sideband is not a new phone and it does not replace iOS. It is a system application and protocol designed to feel like a natural part of the iPhone. The screen on the left is a working demonstration of that idea: one home for your account, contacts, messages, apps, permissions and wallet.
Today, people create a new account, password, profile, payment method and set of permissions in almost every service they use. Sideband turns that relationship around. You keep one user-owned account, and services ask for limited access to the parts they need. You can see that access, set limits and remove it later.
WHAT WOULD USING IT FEEL LIKE?
Your phone creates a secure account that belongs to you, not to an application company.
A verified contact can be used for conversation, payments and shared applications without copying addresses.
The app clearly asks for a capability, such as reading a public profile or sending up to 20 USDC.
Sideband shows the action in plain language and can require Face ID before anything sensitive happens.
Permissions expire, spending can be limited and access can be revoked from one screen.
THE SIX PARTS OF THE SYSTEM
Your Sideband identity can move with you. An app can disappear without taking your identity with it.
Know who you are talking to or paying without treating a long wallet address as a person's name.
Messages are designed to be end-to-end encrypted. The chain proves ownership; it does not publish conversations.
Each app receives a narrow capability instead of permanent access to your full account.
Send, request and approve value from the same place you already know the recipient.
See who can do what, how much they can spend and when their permission ends.
A SIMPLE EXAMPLE
Mira sends you a private request for 12 USDC. Sideband connects that request to the verified Mira already in your contacts. Before payment, it shows the person, amount, asset, network and fee. Your permission rules are checked, Face ID can confirm your presence, and only then is the transaction submitted. You receive one understandable receipt instead of switching between a messenger, a wallet and a block explorer.
Device keys, message content, private contact details, local files, personal settings and biometric approval.
Smart-account ownership, public identity commitments, permission records, application rights and transaction settlement.
Encrypted message relay, push notifications and indexing. These services should be replaceable and unable to take the account.
WHY USE A BLOCKCHAIN AT ALL?
The chain is useful when two people or applications need to agree on ownership, authorization or payment without trusting one company's private database. It gives Sideband a shared source of truth for the account and its public actions. It is not used simply to put everything onchain.
Robinhood Chain acts as the settlement and verification layer. The iPhone remains the interface. Most everyday activity should feel instant and familiar; blockchain details appear only when they help the user understand or verify an action.
PRIVACY IS A BOUNDARY, NOT A FEATURE LABEL
Names, phone numbers, message bodies, photos, private files, recovery secrets and the full social graph do not belong on a public ledger. Sideband is designed to place only the minimum necessary proof onchain. Sensitive information stays encrypted on the device or travels as ciphertext that a relay cannot read.
HOW APPLICATION PERMISSIONS WORK
An ordinary wallet often gives a person a technical signature request that is difficult to judge. Sideband turns that request into a readable rule. For example: "Market may send USDC, up to 20 USDC per payment, until Friday." The user can approve it, reject it or revoke it later without exposing the root account key to the application.
- Limited purpose. An app receives only the capability it needs.
- Limited value. Payments can have per-action and time-based spending limits.
- Limited time. Sessions and permissions have an expiry date.
- Visible history. Important approvals and account actions produce a readable record.
- Immediate revocation. Access can be removed without deleting the user's identity.
SECURITY MODEL
The long-term design uses hardware-backed device keys, Secure Enclave protection and biometric confirmation for sensitive actions. Applications interact with temporary or limited permissions and never receive the root key. Recovery must also be understandable: a lost phone should not mean losing the identity forever, but no company should silently take control of it either.
Security is more than encryption. Sideband must protect users from unclear approvals, unlimited spending rights, fake contacts, replayed transactions, compromised applications and lost devices. These protections require independent review before real assets are supported.
WHAT EXISTS IN THIS BUILD
- Interactive iPhone interface for Home, Identity, People, Messages, Applications, Wallet, Activity and Permissions.
- Working local service for contacts, messages, balances, permission changes, payments and transaction history.
- Encrypted-message primitives using authenticated encryption.
- Permission engine that rejects revoked, expired or over-limit actions.
- Smart-account contracts showing identity, execution and application-policy architecture.
- SwiftUI application source showing how a native iPhone client connects to the system.
- Browsable repository so the implementation can be inspected directly from this page.
The interface and local API work today. The balances, messages and payments in this demonstration use local data and no real asset is moved. The smart contracts are architecture code, not audited production contracts. Sideband should not hold real funds until deployment testing and an independent security review are complete.
WHAT COMES NEXT
- Native build. Complete the Xcode project and run the Sideband interface on an iPhone simulator and physical device.
- Device security. Add Secure Enclave signing, Face ID approval, passkeys and a carefully designed recovery process.
- Test network. Connect the account and payment flow to a safe Robinhood Chain test environment.
- Private communication. Add real end-to-end key exchange, encrypted relay delivery and multi-device sessions.
- Developer platform. Publish capability definitions and a small SDK so applications can request access consistently.
- Production readiness. Expand automated tests, commission contract audits, test recovery and prepare a limited public beta.
WHO IS IT FOR?
Sideband is for people who want the convenience of modern apps without giving every service permanent control over identity, data and money. It is also for developers who want to build useful applications without becoming the custodian of every user's account.
THE GOAL
The goal is not to make the iPhone feel like a crypto terminal. The goal is to make ownership feel normal: your identity follows you, private communication stays private, payments are understandable and every application has clear limits.
THE PHONE REMAINS AN IPHONE.
THE SYSTEM INSIDE IT BECOMES YOURS.
Sideband is an independent project and is not affiliated with Robinhood Markets, Inc.