Tamper-Proof Module Replay Attack Prevention
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Solution Overview
Problem
Existing techniques for protecting data in rewritable openly accessible memory are vulnerable to replay attacks, where attackers can replace current memory data with older data, compromising confidentiality and integrity, as seen in SIM cards and digital rights management systems.
Innovation Solution
A method using a tamper-proof module with a monotonic register and pseudo-random function to generate new encryption and integrity keys, ensuring only current keys are used for data protection, preventing the regeneration of obsolete keys and thus detecting and preventing replay attacks by incrementing the counter value and erasing old data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If data is stored in rewritable openly accessible memory, then data accessibility and storage flexibility are improved, but vulnerability to replay attacks increases
Solution Approach 1:
The system performs preliminary actions by verifying the integrity of existing data using current keys before allowing any operations. The monotonic register is updated in advance to ensure that only current keys are used for subsequent operations, preventing replay attacks before they can occur.
Solution Approach 2:
The system changes the parameter of key validity by using a monotonic register to track and manage key versions. The counter value in the monotonic register is incremented with each key change, ensuring that keys are valid only for specific time periods and cannot be reused from previous states.
2Reliability
If a monotonic register with counter value is used to manage keys, then prevention of replay attacks is improved, but device complexity increases
Solution Approach 1:
The monotonic register serves multiple functions: it stores the counter value for key generation, tracks the state of key validity, and manages the lifecycle of encryption and integrity keys. This multi-functionality reduces the need for separate components while maintaining security.
Solution Approach 2:
The key management system is self-service in nature, automatically generating new keys based on the monotonic register counter, automatically verifying data integrity using current keys, and automatically updating the register state. This eliminates the need for external intervention in key management operations.
3Reliability
If current keys are used to protect data, then data confidentiality is improved, but ability to detect replay attacks decreases
Solution Approach 1:
The system implements feedback by continuously verifying data integrity against current keys derived from the monotonic register. The verification process provides feedback about the authenticity of data, and the monotonic register provides feedback about key validity states, enabling detection of replay attempts.
Solution Approach 2:
The system performs preliminary integrity verification using current keys before allowing any data operations. This preliminary action ensures that any replayed data from previous states will be detected and rejected, as the verification will fail against the current key derived from the updated monotonic register.
Data Source
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AI summary
A device (e.g., mobile device) and method are described herein that can protect data stored in a rewritable openly accessible memory from replay attacks by using an integrity key and an encryption key to en/decrypt the data, integrity protect the data via a MAC calculation, and verify the data.