TrustFi Security

Review of Security Best practices

Physicaly Uncloneable Function

  • PUF (Physical Unclonable Function) is a physical property based on the molecular structure variation of same materials. The variation causes sophisticated differences generated the manufacturing process.

  • PUF is created through the chip manufacturing process.It utilizes its unavoidable and uncontrollable variations at a molecular level, which creates each chip unique.

Why PUF?

  • PUF maintains its uniqueness throughout the manufacturing process.

  • The functionality of PUF is based on a challenge-response mechanism in which the mapping between a challenge and the corresponding response is dependent on the complex and variable nature of a physical material.

TPM or SE integration as applicable

• G3 Security Processor

G3 Key Features
  • PUF(Physical Unclonable Function)
  • Embedded Flash memory
  • Multiple Cryptographic algoritms
  • Interfaces
• PUF on G3 security processor
  • PUF supports key generation
  • The data stored in G3 is encrypted using a PUF key and it is decrypted when using the data.
  • The private key of ECC is generated by PUF and a key received from external site can be used.
  • When using AES and SM4 algorithms, a PUF key supports encryption and decryption.
• Cryptographic Algorithms

The G3 supports multiple cryptographic algorithms
  • Symmetric key algorithm: AES, DES and SM4
  • Asymmetric key algorithm:
  • ECC (ECDSA and ECDH) with secp256r1 (NIST P256)
  • ECC sm2p256 curve and SM2 signature algorithm
  • Hash algorithm: SHA256.

Physical Attack Defence

• Types of hardware attack
  • Invasive attack
    • Micro probing
    • Fault injection
    • Reverse engineering
    • Chip modification
    • FIB
  • Non-invasive attack
    • Side channel attack (Power analysis, DPA/SPA/CPA etc.)
    • Electro-magnetic analysis
    • Timing attack
    • Glitch attack
    • Data remanence in NVM
• Hardware attack prevention technology
  • Active shield on top of semiconductor wafer
    • Defence for various type of invasive attack
  • Probing attack to VIA PUF
    • PUF cells in a form of standard cell
    • Scattered thourghout the chip
    • Even when detected, PUF value cannot be read without cross-sectional view
    • Number of probing on one chip is limited (because approxmately the 4~5 probing on semiconductor wafer excuted, then the wafer will be broken.)
  • Defence for DPA attack
    • Power consumption that does not change even with chages in cryptographic calcualtion
    • Dummy calcualtions
    • Power load balancing