Parallel Message Authentication Tag Generation Using Single Block Cipher Key
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Solution Overview
Problem
Existing message authentication schemes, such as CMAC and PMAC, require precomputation and are not parallelizable, making them unsuitable for environments with frequent key changes or limited resources, and they fail to meet the requirements of quasi-optimal computation cost, parallelizability, using one block cipher key, and no precomputation.
Innovation Solution
A tag generation device and method that divides messages into blocks, performs parallel encryption and post-processing using one block cipher key, and repeats the process until the number of blocks is reduced to a predetermined value, allowing for efficient tag generation without precomputation and with minimal block cipher calls.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If CMAC or PMAC is used for message authentication, then security is improved, but precomputation is required and parallel processing is not enabled
Solution Approach 1:
The message is divided into multiple blocks that can be processed in parallel. The patent applies parallel encryption to multiple message blocks simultaneously, then combines the results through post-processing to generate the authentication tag, enabling parallel processing while maintaining security
Solution Approach 2:
The patent eliminates the need for precomputation by directly processing message blocks in parallel without requiring preliminary encryption of zero blocks or other precomputed values, thus removing the preprocessing bottleneck present in CMAC and PMAC
2Reliability
If CMAC or PMAC is used for message authentication, then security is improved, but precomputation and memory storage are required
Solution Approach 1:
The patent extracts and eliminates the precomputation step from the authentication process. By removing the requirement to precompute and store intermediate values, the scheme reduces memory usage while maintaining security through direct parallel processing of message blocks
3Reliability
If frequent key changes are implemented, then security is improved, but processing overhead increases due to precomputation requirements
Solution Approach 1:
The patent eliminates preliminary precomputation steps, allowing keys to be used immediately for parallel message authentication without requiring advance preparation or storage of precomputed values, thus reducing overhead during frequent key changes
4Productivity
If parallel processing is enabled, then productivity is improved, but computation cost increases
Solution Approach 1:
The patent segments the message into parallelizable blocks that can be encrypted simultaneously, then combines results through efficient post-processing, achieving parallel speedup without requiring excessive computational resources beyond the parallel encryption operations
Data Source
AI summary
Provided are a tag generation device, method and program which are capable of parallel execution, need no precomputation, and are capable of reducing block-cipher calls to the minimum necessary using one block cipher key when a tag to be attached to a message is generated. A tag generation device is provided with: an input means (100) which divides a message into a plurality of blocks; an intermediate chunk hash means (101) to which the blocks included in the message are inputted as an object to be processed, and which, in units of a predetermined number of blocks, using one key, executes encipherment processing and post-processing of encipherment on the blocks in parallel to generate an intermediate output, and designates, as a next object to be processed, a message created by coupling the intermediate output and unprocessed blocks; and a final chunk hash means (102) which, when the number of block in the message or the number of blocks in the message created by coupling the intermediate output and the unprocessed block is a predetermined value or less, generates a tag corresponding to the message.