Card-Based Key Store for Secure Blockchain Signing
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Solution Overview
Problem
User devices such as mobile phones or laptops storing cryptographic keys for blockchain networks are vulnerable to loss, theft, and hacking, leading to potential loss of access and funds, and are difficult to use in certain circumstances.
Innovation Solution
A card with a processor and memory storing cryptographic keys is used to sign and verify blockchain interactions, allowing secure storage and use of keys for transactions, even in environments lacking compatible hardware or software.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If cryptographic keys are stored on a personal computer, then accessibility and ease of operation are improved, but security and protection against unauthorized access deteriorate
Solution Approach 1:
The system divides the cryptographic key storage into two separate locations: a secure element (such as a smart card or hardware token) for secure storage and a personal computer for convenient access. The key material is segmented between these components, with the secure element holding the private key and the PC holding only public keys or encrypted versions, thus achieving both security and accessibility.
Solution Approach 2:
A secure element acts as an intermediary between the user and the cryptographic key. This intermediary provides a trusted computing platform that performs cryptographic operations securely while allowing the user to access cryptographic services conveniently through their personal computer. The secure element mediates all key operations, ensuring security while enabling ease of use.
2Reliability
If cryptographic keys are stored on a smart card, then security and protection against unauthorized access are improved, but accessibility and ease of operation deteriorate
Solution Approach 1:
The system makes the smart card multi-functional by enabling it to work with multiple applications and services across different computers and platforms. The secure element can be used for email encryption, file protection, authentication, and other cryptographic services, making it a universal security solution that enhances accessibility while maintaining security.
Solution Approach 2:
The secure element in the smart card serves as an intermediary that provides secure cryptographic services while being accessible through standard interfaces. It mediates between the user's convenience needs and security requirements by performing all sensitive operations internally and presenting only the necessary results to the user.
3Ease of operation
If cryptographic keys are exported to another computing device, then accessibility is improved, but security and protection against unauthorized access deteriorate
Solution Approach 1:
Instead of copying the actual cryptographic key, the system creates and exports only a public key or an encrypted version of the key to external computing devices. The sensitive private key remains securely stored in the secure element and is never exported. This copying approach allows accessibility for legitimate operations while maintaining security against unauthorized access.
Solution Approach 2:
The system extracts only the necessary non-sensitive components of the cryptographic key (such as public keys or encrypted forms) from the secure element and stores them externally. The critical private key material remains extracted and retained within the secure element, allowing external devices to perform cryptographic operations without compromising the security of the actual key material.
4Reliability
If a cryptographic key store is implemented, then security and protection against unauthorized access are improved, but device complexity increases
Solution Approach 1:
The secure element is designed as a self-contained cryptographic processing unit that performs all cryptographic operations internally without requiring complex external key management infrastructure. It automatically manages key generation, storage, and operations, reducing the overall system complexity while maintaining high security standards.
Solution Approach 2:
The system merges the secure element with existing personal computing devices or communication equipment, integrating cryptographic functionality into devices users already possess. This consolidation eliminates the need for separate complex key management systems while providing enhanced security through the embedded secure element.
Data Source
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AI summary
A method includes a sender device operated by a sender receiving a receiver address associated with a receiver. The sender device prompts the sender to interact a card comprising a processor and a memory storing a sender public key and a sender private key of a sender public-private key pair associated with a blockchain network, the card held by the sender. The sender device transmits interaction data including the receiver address, a sender address of the sender, and a value to the card. The processor of the card retrieves the sender private key and signs the interaction data to produce signed interaction data. The sender device receives the signed interaction data and the sender public key. The sender device transmits the interaction data and the signed interaction data to the blockchain network. The blockchain network records the interaction data and the signed interaction data in a block of a blockchain.