Non-interactive Certificate Update Protocol for IoT Security

The patent applies preliminary action by pre-generating certificate bundles at the CA server before they are needed by IoT devices. The CA server creates multiple certificate bundles in advance (cert0, cert1, cert2, etc.) with corresponding time windows, and stores them ready for distribution. This eliminates the need for devices to communicate with the CA during certificate updates, as they can independently retrieve pre-prepared certificates based on time information, thus improving security through frequent updates while reducing communication overhead.

The patent implements self-service by enabling IoT devices to autonomously determine which certificate bundle to use based on the current time and information embedded in the certificate itself. Each certificate contains a time window indicator, allowing the device to automatically select the appropriate certificate without contacting the CA server. This self-service mechanism reduces communication costs while maintaining security through periodic certificate updates.

The patent applies copying by creating multiple copies of certificate bundles in advance at the CA server. Instead of processing individual certificate requests from numerous IoT devices, the CA generates and stores multiple identical or variant certificate bundles (cert0, cert1, cert2, etc.) that can be distributed to devices. This copying approach allows the system to handle large numbers of devices without requiring proportional increases in processing hardware, as the heavy computational work is done beforehand during certificate bundle generation.

The patent uses preliminary action to perform certificate generation and validation work before deployment to IoT devices. The CA server pre-computes certificate bundles with embedded time windows and validity information, storing them ready for distribution. This shifts the computational burden from runtime processing (which would require expensive hardware) to offline preparation, enabling the system to scale to large numbers of devices without proportional increases in hardware costs.

The patent implements self-service by enabling IoT devices to autonomously manage certificate updates using time information embedded in the certificates themselves. Each certificate contains a time window indicator that allows the device to independently determine when to update its certificate without contacting the CA server. This eliminates communication overhead during certificate updates, preserving IoT node battery life and operational lifetime while still enabling frequent certificate updates for security.

The patent applies preliminary action by pre-embedding time window information and update instructions within the certificate bundles during their generation at the CA server. This preliminary encoding of update timing information allows IoT devices to autonomously perform certificate updates at appropriate intervals without needing to communicate with the CA, thus enabling frequent updates for security while minimizing communication that would drain device batteries and reduce operational lifetime.