“Will my new face-recognition smart lock open if someone just holds a printed photo in front of it?”
Short answer: Not if it’s powered by 3D structured-light technology—and certified to bank-grade liveness standards like ours.
Below we unpack why, compare the three mainstream 3D sensing schemes, and show you exactly what to demand from a lock that is supposed to guard the people you love.
1. How Face Unlock Can Be Tricked (and How It Can’t)
| Attack Vector | 2D Photo / Video | 3D Mask (resin, silicone) | Real Human Face |
|---|---|---|---|
| 2D camera only | ✅ Easy cheat | ✅ Often works | ✅ Works |
| Stereo vision (low-grade) | ✅ Possible | ⚠️ Sometimes | ✅ Works |
| ToF (basic) | ❌ Blocked | ⚠️ Possible | ✅ Works |
| 3D Structured-Light + AI liveness | ❌ Blocked | ❌ Blocked | ✅ Works |
Take-away: Without true depth + liveness checks, a “smart” lock is just an expensive electric latch.
2. The Three Flavors of 3D Sensing—In Plain English
| Technology | What It Does | Pros | Cons | Best Use-Case |
|---|---|---|---|---|
| Structured-Light (our choice) | Projects a speckle pattern, reads how your face distorts it. Creates 0.5 mm-resolution depth map. | • Ultra-high accuracy • Works in total darkness • Lowest false-accept rate (<0.0001 %) • Bank cards & payment phones use it | • Slightly higher BOM cost • Needs an IR projector | Premium residential locks, financial payment devices |
| ToF (Time-of-Flight) | Measures how long light takes to bounce back. | • Fast (fps > 100) • Small module • Long range | • Struggles in sunlight • Lower precision (±2–4 mm) • Easier to fool with 3D masks | Robotics, VR, mid-range phones |
| Active Stereo | Two IR cameras + projected texture; triangulates depth. | • Cheap • Good in sunlight | • Baseline makes module big • Mediocre depth quality • Still vulnerable to high-res masks | Entry-level phones |
Bottom line: For a security product that lives on your front door, only structured-light gives both resolution and liveness certainty.
3. Our Lock’s 3-Step “Anti-Photo” Pipeline
- 30,000-Dot IR Pattern
A MEMS mirror paints an invisible, non-repeating speckle grid on your face in 20 ms. - AI Depth Reconstruction
A neural net compares the reflected pattern against a library of 3D face meshes; flat objects (paper, tablets, 4K prints) score zero depth variance → instant reject. - Liveness Check via Micro-Texture & Blood-Flow
Sub-millimetre skin reflectance changes caused by pulse are extracted; no flow = no entry.
Result: Certified FIDO Level-2 & UnionPay BCTC (Bank Card Test Center) liveness grade—the same hurdle Apple Pay and Alipay must clear.
4. Lab Test We Invite Every Skeptic to Watch
| Attack Item | Result |
|---|---|
| 6 × 4-inch glossy passport photo | ❌ Rejected in 0.2 s |
| 1080p phone video loop, brightness maxed | ❌ Rejected |
| 3D resin mask @ 0.3 mm accuracy | ❌ Rejected |
| Twins (fraternal, 92 % DNA match) | ✅ Only enrolled twin passes |
5. FAQ—What Customers Ask Most
Q: Does it work at night without porch lights?
A: Yes. IR projector is invisible to humans but floods your face up to 2 m away.
Q: Sunlight overload?
A: Structured-light is immune to IR interference because we modulate the dot code; the sensor locks onto our specific frequency band.
Q: Power draw?
A: 8 × AA lithium cells = 10,000 unlocks, or ≈ 12 months normal family use.
Q: Kids & elderly?
A: Minimum height 1.2 m; for toddlers we include NFC wristbands.
6. Spec Sheet at a Glance
| Sensor | 3D Structured-Light, 30 K dots, 940 nm |
|---|---|
| FAR (False-Accept) | < 0.0001 % |
| FRR (False-Reject) | < 0.5 % |
| Liveness Cert | FIDO L2, UnionPay BCTC, ISO 30107-3 |
| Unlock Time | < 0.8 s (include motor) |
| Working Range | 0.4 – 1.2 m |
| Weather | IP65, –30 °C – 70 °C |
7. Key Message to Take Home
A photo, a tablet video, or even a $300 resin mask will not open our 3D structured-light smart lock.
We didn’t reinvent the wheel—we simply borrowed the same sensor stack that protects your banking apps and put it in the device that protects your front door.
Lock the past. Unlock the future.
