TRUST PROVISIONING Related Hardware Embedded Secure Elements for Mobile Phone applications We leave the world of cryptography for a while. We understand that where online PKI is not possible, the secret keys must be exchanged and kept secret. A smartcard, or a secure element, are good way of securely storing a secret, like a key. The processor using the key for the computation is in the smartcard as well, as such the key never leaves it’s secure environment. But such keys have to be loaded on the smartcard once. This is how it works generally:

Smart Card Initialization & Personalization Service Provider (bank) Card 5566..0001 – Mr Bianchi Card 5566..0001 – Mr Bianchi Card 5566..0002 – Mr Gallo Card 5566..0002 – Mr Gallo Card 5566..0003 – Mr Rossi Card 5566..0003 – Mr Rossi O.S. Provider ROM Mask, EEPROM Image, Silicon Manufacturer Card Vendor Wafer Testing … Pre-perso Personalization Card 5566..0001 Mr Bianchi Card 5566..0002 Mr Gallo Card 5566..0003 Mr Rossi SMART CARD 5566 .. 002 Mr Gallo Flow of Trust Mr Gallo Flow of Hardware Press <space> once!

Trust Provisioning Initialization & Personalization service provider Service Provider(s!) (bank) Trusted Service Manager O.S. Provider ROM Mask, EEPROM Image Silicon Manufacturer Mr. Koch OTA IC Personalization Mr Koch – 040-238679 OTA Diffusion, Wafer Testing, Initialization (1Key4Die),… X Uid..001 Uid..002 Uid..00n Uid..001 Uid..002 Uid..00n 001 002 Non trusted OEM/ODM 00n 001 MNO 00n 002 001 002 Distribution / Retail 00n 001 End

How Keys and Certificates are created Start public Silicon Manufacturer Public/Private Key Pair NXP private key securely stored in NXP HSM private public private Generate IC-specific Public/Private Key Pair Key Generator Secure Key Storage Create Device Certificate Body Signing Hardware Secure Module (HSM) Calculate Hash of Certificate Body Body Signed Hash Example Signature Sign Hash with NXP Private Key Insert Device Certificate + IC-specific Private Key in Embedded SE Chip ESE Chip Ready

Offline authentication HOST (MCU) CLIENT (Authentication Device) Body … Public Key Signed HASH Root CA Certificate Body … Public Key Signed HASH Device Certificate Body … Public Key Signed HASH Device Certificate Request certificate Send certificate Client Certificate is genuine Private Key Validate certificate NOK OK Rnd# Send challenge Sign(Rnd#) Sign challenge Send response Validate response Client knows its private key NOK Continue service OK stop

Client-authenticated TLS handshake ClientHello Certificate ClientKeyExchange CertificateVerify ChangeCipherSpec Finished RNDa+caps ServerHello Certificate CertificateRequest ServerHelloDone ChangeCipherSpecs Finished RNDb+method selection Certificate verification Server certificate+CA sign Client certificate+CA sign Secret key Certificate verification Transaction signature

Hands-on: Example of a TLS link Using A70CM