US Patent 10521618 Methods and apparatus for secure root key provisioning

The present disclosure describes apparatuses and techniques for secure root key provisioning. In some aspects, a stream of entropy bits is generated based on analog noise. From the stream of entropy bits, entropy symbols are constructed and used to modulate bits of a unique chip identifier to provide a block of modulated symbols. A hash digest of the block of modulated symbols is then calculated to generate a device-level root key. This device-level root key written to a write-only register of a one-time programmable (OTP) memory controller for subsequent writing into an OTP memory. By so doing, unauthorized entities can be prevented from accessing the device-level root key during the secure key provisioning process.