OTP Key Storage Using Wafer Energy Harvesting and Key Erasure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing key storage methods in semiconductor chips are vulnerable to hacking and require additional secure environments for programming, leading to increased costs.
Innovation Solution
A key storage device and method that utilizes an energy harvester to collect energy particles during fabrication, enabling automatic key transfer to an OTP device and erasing the original key value, ensuring security without additional costs or facilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If key value is programmed during RTL design phase into fuse-like storage, then key value exists in chip when fabricated, but key value is visible to hackers under microscope
Solution Approach 1:
The key value is pre-programmed into the fuse-like storage structure during the RTL design phase and chip fabrication process. This preliminary action ensures the key exists in the chip before any potential security threats arise, allowing the system to have the key ready for immediate use while maintaining security through the invisible storage mechanism
Solution Approach 2:
The invention creates a copy mechanism where the key value is transferred from the visible fuse-like storage to invisible storage (such as OTP or anti-fuse) after fabrication. This copying process allows the system to maintain both a visible reference during manufacturing and a secure invisible copy for operational use, eliminating hacker visibility while preserving key functionality
2Reliability
If key value is written into invisible storage after chip fabrication, then key security is improved, but additional secure environment is required which introduces additional manufacturing costs
Solution Approach 1:
The invention merges the key programming process with the standard chip fabrication process by utilizing the existing fabrication environment to program both the fuse-like storage and the invisible storage (OTP/anti-fuse) simultaneously. This integration eliminates the need for separate secure programming environments, thereby maintaining key security while avoiding additional manufacturing costs
Solution Approach 2:
The fabrication process is designed to serve multiple functions: it simultaneously programs the fuse-like storage with the key value and programs the invisible storage (OTP or anti-fuse) with the same key value. This multi-functionality allows the same fabrication environment to achieve both visible and invisible key storage, eliminating the need for additional secure facilities
3Reliability
If additional secure environment is introduced to program key value after fabrication, then key security is enhanced, but manufacturing process complexity increases
Solution Approach 1:
The invisible storage (OTP or anti-fuse) is prepared and configured during the chip fabrication process itself, before the chip leaves the fabrication environment. This preliminary action ensures that the secure storage mechanism is already in place and synchronized with the fuse-like storage, eliminating the need for complex post-fabrication secure programming processes
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides secure key storage by making the key value invisible to hackers and eliminating the need for additional secure environments, thus enhancing security and reducing costs.
Implementation Method 1
The energy harvester is configured to collect energy particles during a fabrication process of a wafer which comprises the key storage device, in order to generate a regular voltage
Data Source
AI summary
A key storage device and a method for writing a key value into an one-time-programmable (OTP) device are provided. The key storage device includes an energy harvester, a controller, a hardware key device and the OTP device. The energy harvester is configured to collect energy particles during a fabrication process of a wafer which includes the key storage device, in order to generate a regular voltage. The controller is configured to enable a key transfer procedure when the regular voltage reaches a predetermine level. The hardware key device is configured to provide a pre-existing key value. The controller reads the pre-existing key value from the hardware key device, and writes a key value into the OTP device according to the pre-existing key value. After the OTP device stores the key value, the controller erases the pre-existing key value within the hardware key device.