# Amin

- **Event:** [Meta Global AI Developer Hackathon](https://cerebralvalley.ai/e/meta-ai-developer-hackathon)
- **When:** Oct 26, 12:00 PM – Nov 4, 9:00 PM (EST)
- **Where:** Online
- **Team:** [Amin Pinjari](https://cerebralvalley.ai/u/aminpinjari)
- **GitHub:** https://github.com/Pinjari/wavetone
- **Demo video:** https://github.com/Pinjari/wavetone/blob/main/Wavetone_Demo.mp4
- **Gallery:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery
- **Page:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1666

Deepfakes defeat ears. They don't defeat hardware.

Voice cloning now needs only seconds of audio, and it is being used
for "family emergency" and fake bank-officer calls that walk victims
into UPI payments while still on the phone. Statistical deepfake
detectors are the wrong defense: probabilistic, always one model
behind, and they produce no proof a user can act on mid-call.

Wavetone proves who is really on the call — cryptographically:

1) OUT-OF-BAND (hardware proof): ECDSA P-256 challenge-response
signed inside Android StrongBox/TEE, relayed over a lightweight
WebSocket. Verdict: HARDWARE VERIFIED.

2) IN-BAND ACOUSTIC (paired-device proof, zero internet): a
pure-Kotlin BFSK modem (1600/2400 Hz, ~640 ms burst) carries a
truncated HMAC-SHA256 + CRC-8, decoded by a Goertzel engine —
no native DSP libraries. Verdict: PAIRED DEVICE VERIFIED, labeled
honestly (paired-secret possession, not enclave proof).

3) SCAM-BREAKER: a CallScreeningService seeds sessions for real
calls. If proof fails or the caller is unpaired, an
AccessibilityService locks UPI/banking apps ("Pay ₹", "Enter UPI
PIN") behind a crimson shield until the call ends (auto), the user
ends it from the shield, or holds a 3-second emergency override.

Sessions are AES-256-GCM encrypted and persisted, so protection
survives process death mid-call and lifts itself on hang-up.

Built and verified end-to-end: hand-rolled SHA-256/HMAC and DSP
validated against NIST/RFC vectors; 35 unit tests; 6 instrumented
tests on a physical Pixel 9 Pro XL (StrongBox signing, true
over-the-air speaker→mic decode, replay rejection, ciphertext at
rest); Lint at 0 errors; 2.4 MB release APK; CI on every push.

## More from Meta Global AI Developer Hackathon

- [WellPilot](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1663)
- [CandiVision](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1664)
- [VAM Tech Cabal](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1665)
- [Ibrahim Imam](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1667)
- [LiveSplat](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1668)
- [CrewOps](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1669)

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Markdown version of https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1666. Site index for agents: https://cerebralvalley.ai/llms.txt · full text: https://cerebralvalley.ai/llms-full.txt