White-Box Encryption Key Table Generation and Misty Algorithm Configuration
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Solution Overview
Problem
Conventional white-box cipher algorithms face inefficiencies due to additional operations for protecting cipher keys and difficulty in adapting to changes in unit input size based on application environments, leading to reduced performance.
Innovation Solution
An encryption apparatus and method that generates encryption and decryption key tables from random values, using a Misty structure with adjustable branches and rounds based on available memory and security levels, allowing for efficient encryption and decryption processes without additional key protection operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional white-box cipher algorithms use additional operations to protect cipher keys, then security is improved, but processing efficiency deteriorates by a factor of several tens
Solution Approach 1:
The cipher key is segmented into multiple key tables (first key table, second key table, etc.), each storing portions of the key material. This segmentation allows the encryption algorithm to access only necessary key portions during processing, eliminating the need for additional protective operations while maintaining security. The key schedule generator divides the original key into distributed key material across multiple tables.
Solution Approach 2:
Key tables are pre-generated and stored before the encryption process begins. The key schedule generator creates these key tables in advance using the original cipher key, so that during actual encryption, the algorithm can directly use the pre-prepared key material without performing additional key protection operations, thus maintaining both security and efficiency.
2Device complexity
If conventional white-box cipher algorithms use fixed base algorithm structures, then implementation is simplified, but adaptability to different unit input sizes deteriorates
Solution Approach 1:
The encryption algorithm is designed with dynamic parameters including variable number of branches, variable number of rounds, and variable key table sizes. These parameters can be adjusted based on the unit input size requirements of different applications. The algorithm structure allows flexible configuration while maintaining a relatively simple base implementation framework.
Solution Approach 2:
The algorithm allows changing key parameters such as the number of branches, number of rounds, and key table dimensions to adapt to different input sizes. By modifying these parameters, the same base algorithm can efficiently handle various input sizes without requiring complete redesign, thus improving adaptability while keeping implementation complexity manageable.
Data Source
AI summary
Disclosed are an apparatus and method for encryption. The encryption apparatus includes a key table generator configured to generate at least one encryption key table from random values obtained from a seed value and generate at least one decryption key table from the at least one encryption key table; an algorithm generator configured to generate an encryption algorithm having a Misty structure that has a round function to which the at least one encryption key table is applied and a decryption algorithm having a Misty structure that has a round function to which the at least one decryption key table is applied; an encryptor configured to encrypt plaintext data with the encryption algorithm; and a decryptor configured to decrypt encrypted data with the decryption algorithm.