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Recovery Architecture

Interstellar implements a flexible, threshold-based recovery architecture designed to provide secure account restoration without seed phrases, centralized custody, or external KYC providers. This system supports biometric-first, multi-factor, and hardware-anchored recovery workflows—all executed within a trusted execution environment (TEE).

Recovery Philosophy​

Traditional recovery mechanisms (e.g., mnemonic seed phrases or custodial email/password systems) create single points of failure and poor user experience. Interstellar's approach is:

  • Non-custodial: All recovery logic is enforced on-chain and inside the TEE.
  • Threshold-based: Multiple recovery items may be registered, with customizable policies (e.g., 2-of-3).
  • Hardware-compatible: Includes support for NFC tags and secure files (VCA tokens).
  • Biometric-native: Recovery can be initiated through a biometric challenge on a trusted device.

Types of Recovery Items​

Recovery items are cryptographically registered with the user’s account and may include:

  • NFC Tags: Everyday physical objects (cards, wearables) registered and verified via UID hashing.
  • VCA Tokens: Secure files backed by garbled circuits, stored in the cloud or offline.
  • Other mobile accounts (planned): Additional devices or users in a social recovery graph.

Each item is mapped to an item account ID, which is used by the runtime to enforce threshold recovery logic.

Recovery Configuration​

When setting up recovery, the user may define a threshold policy such as:

  • Total registered items: 3

  • Threshold required to recover: 2

This policy is enforced inside the TEE and stored in encrypted runtime state. During recovery, the TEE checks the combination of presented items (e.g., NFC tag + VCA token) and only proceeds if the threshold is satisfied.

Key Recovery Steps​

  1. Recovery Initiation: Triggered via the mobile app on a new device using biometric + recovery item scan.
  2. Item Verification: Each recovery item (tag, file) is re-hashed and matched against on-chain registration.
  3. Threshold Check: If the required number of verified items are present, recovery is unlocked.
  4. New Key Registration: The new device's SE-based mobile proxy account is bound to the root account.

Advantages​

  • No seed phrase or passwords
  • No centralized service dependency
  • Supports physical + digital backup
  • TEE-verifiable and privacy-preserving

The Recovery Architecture lays the foundation for resilient and user-friendly fallback strategies, offering users strong guarantees of safety and recoverability—without sacrificing self-custody or user experience.