M ICRO - AND N ANO -S ENSOR FOR I O T S ECURITY US-K OREA F ORUM ON N - PowerPoint PPT Presentation

Y OUNGHYUN K IM U NIVERSITY OF W ISCONSIN –M ADISON M ICRO - AND N ANO -S ENSOR FOR I O T S ECURITY US-K OREA F ORUM ON N ANOTECHNOLOGY @ N ANO K OREA , J ULY 13, 2018, I LSAN , K OREA

V ARIATIONS IN S EMICONDUCTOR M ANUFACTURING � 2 Fast Slow Fast Slow ▸ Random variations in semiconductor manufacturing process ▸ Sources: gate oxide thickness, random dopant fluctuations, device geometry ▸ Consequences: variations in performance (speed, sensitivity, etc.) ▸ Should be minimized, cannot be eliminated ▸ Can we take advantage of it?

P HYSICALLY U NCLONABLE F UNCTIONS (PUF) � 3 Process variation Unique fingerprint PUF key SRAM Reset state Unique random 
 number DRAM Retention capability 0101101101000… RF transmitter Propagation delay Arbiter chain Phase/magnitude error Cell charge leakage Ring oscillator

PUF A PPLICATION : T WO -F ACTOR A UTHENTICATION � 4 + = Username 2348 ******** Smartphone USB 
 OTP 
 Password drive generator Something you KNOW Something you HAVE = PUF device

CMOS I MAGE S ENSOR - BASED PUF � 5 G R Row decoders B G Column readout circuit Dark Bright pixels pixels

CMOS I MAGE S ENSOR - BASED PUF � 6 ▸ Unique fixed pattern noise (FPN) appears in the captured images ≠ ≠ Same model, different noise patterns

P ROTOTYPING AND E VALUATION � 7 ▸ Camera2 API Sony IMX377 ▸ Raw and jpeg images (12 megapixels) ▸ Temperature-controlled chamber ▸ Maximum ISO ▸ Minimum shutter speed ▸ Additional experimental results on Google Nexus 5 available in Google Nexus 5X the paper

E XPERIMENTAL R ESULTS : K EY E XTRACTION � 8 IMX377 #1 IMX377 #2 IMX377 #3 Bright pixel Challenge map Dark pixel Bit 1 Reference response Bit 0