The problem Hollow Vault solves

**Numbers below were validated against the running system:** gas costs (~15.5k verify / ~20.3k attest) by `forge test`; test counts (127 unit / 52 e2e / 4 Foundry) by `npm run test:unit && npm run test:e2e && forge test`; live deployment confirmed at `hollow-vault.vercel.app/api/health` (mode: real, signerType: kms). Sony PS3 (Dec 2010, fail0verflow @ 27C3) and Android Bitcoin SecureRandom (Aug 2013) are public record.

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Every Web3 wallet keeps the private key on the user's device. **Three failure modes follow that have already cost real users real money** — and no software-only fix works without changing where the key lives.

Hollow Vault moves the key into SpaceComputer's Orbitport KMS and binds 32 bytes of cosmic randomness (from Orbitport's satellite-attested cTRNG) into every signature.

## What it makes safer

**🔑 Broken-RNG ECDSA key extraction.** Sony PS3 and Android Bitcoin wallets lost funds when two signatures shared a nonce — the math leaks the key. Hollow Vault mixes externally-sourced cosmic entropy into every signed payload, so even a broken local CSPRNG can't produce a colliding nonce. Live in-browser proof at `/vulnerability`: recovers a key from two reused-nonce signatures in ms, then shows the same attack on Hollow Vault returns nothing.

**🔧 Key seizure / forced extraction.** Your laptop holds only OAuth credentials, never the secp256k1 key. Lose the laptop → revoke the credentials → nobody can produce new signatures with that key. The key itself sits in a TEE today, with on-orbit secure elements on SpaceComputer's roadmap.

**🕒 Backdating.** Cosmic seed is in the signed payload; verifier checks freshness (24h past / 2min future); the satellite-attested timestamp ties each signature to a draw that didn't exist before. Receipts can't be retroactively forged.

## What it makes easier

- **SIWE / EIP-712 / standard `ecrecover`** — signatures are bit-compatible; no contract changes
- **drand-using dapps** — JSON-shape adapter at `/info`, `/public/latest`, `/public/{round}` for cosmic-attested randomness
- **On-chain verification** — `HollowVaultVerifier.sol` (Foundry-tested) verifies at **~15.5k gas**, attests at **~20.3k gas**

## New things it unlocks

- **Whistleblower receipts** — journalist's priority-of-disclosure attestation survives subpoena; once credentials revoke, no party can forge new signatures from that key
- **AI agent wallets** — per-agent KMS keys with policy bounds (`maxPerTxWei`, `allowedRecipients`) + JSONL audit log; compromised agent process can't exfiltrate the key
- **Cosmic-timestamped public commitments** — sign now, anchor on-chain within 24h, durable proof of when
- **Sealed-bid auctions** — bid commits to a seed that didn't exist when the bid was formulated

Open-source at `github.com/batikanor/HollowVault`, live at `hollow-vault.vercel.app`, locked behind 127 unit + 52 e2e + 4 Foundry tests.