Cryptographic Key Expansion for Brute Force Resistance
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Solution Overview
Problem
The increasing computational power has heightened the risk of successful brute force attacks on data communication, necessitating improved security measures in data transmission between electronic devices.
Innovation Solution
A method of data communication that involves obtaining a base key and determining an updated key of at least N+M bits by performing cryptographic operations such as hash functions or encryption functions at least 2M times, significantly increasing the key length and entropy to enhance security.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the base key length is increased to combat brute force attacks, then security is improved, but processing time and computational resources increase
Solution Approach 1:
The patent performs key expansion operations in advance before the actual data encryption is needed. By pre-computing the expanded key using hash functions or encryption functions, the system prepares stronger security credentials beforehand, allowing the actual encryption process to use the pre-prepared long key without adding significant processing delay to the critical encryption path.
Solution Approach 2:
The key expansion process is divided into multiple iterative steps, where a cryptographic function is applied repeatedly M times to transform the base key into an expanded key. This segmentation allows the computationally intensive work to be broken down into manageable iterations, with each iteration building upon the previous result, balancing security strength with processing efficiency.
2Reliability
If cryptographic operations are performed multiple times to expand key length, then security against brute force attacks is enhanced, but device complexity increases
Solution Approach 1:
The patent employs standard, widely-available cryptographic functions (such as AES encryption or SHA hash functions) that can be implemented using existing hardware and software components. By using universal, well-understood cryptographic primitives, the system achieves enhanced security through multiple iterations without requiring specialized or complex custom cryptographic algorithms, thus limiting the increase in device complexity.
3Reliability
If the effective key length is increased by M bits, then resistance to brute force attacks is significantly improved, but energy consumption increases
Solution Approach 1:
The patent adjusts the parameter M (number of additional bits) to achieve the desired security level. By carefully selecting M based on the specific security requirements and computational constraints of the application, the system optimizes the balance between security enhancement and energy consumption, avoiding unnecessary over-provisioning of key length that would waste energy.
Data Source
AI summary
Devices and methods of data communication between a first electronic device and a second electronic device are disclosed. The disclosed methods optionally comprises obtaining, at the first electronic device, a base key having a length of N bits; determining, at the first electronic device, a first updated key based on the base key, wherein the first updated key has a length of at least N+M bits, M is larger than 4, and wherein determining the first updated key comprises performing a cryptographic operation, such as a hash function, at least 2M times; and encrypting, at the first electronic device, data with the first updated key for provision of cipher data.