Digital Audio Stream Scramble System Using Coefficient Modification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing digital audio protection systems fail to provide high security against piracy, as they often rely on encryption methods that modify the audio flux structure, making them vulnerable to unauthorized use and degradation of audio quality.
Innovation Solution
A process that modifies specific coefficients of the digital audio flux while maintaining compliance with standard formats, allowing for the reconstruction of the original flux using additional information, ensuring the protection is based on the bitstream structure and reduces the volume of information required for decoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If encryption methods are used to protect digital audio flux, then security against piracy is improved, but the audio flux structure is modified and vulnerability to unauthorized use increases
Solution Approach 1:
The patent applies parameter changes by modifying specific coefficients (scale factors and Huffman codes) within the audio flux structure rather than encrypting the entire structure. This allows maintaining the standard MP3 format while protecting against piracy by altering parameters that control audio quality perception.
Solution Approach 2:
The invention implements local quality protection by selectively modifying only certain coefficients in the audio flux that correspond to perceptually important frequency bands. This localized approach provides security where needed while preserving overall audio quality and format compatibility.
2Reliability
If audio signal is degraded to prevent piracy, then security is improved, but audio quality is reduced
Solution Approach 1:
The patent uses partial action by modifying only a subset of coefficients in the audio flux rather than degrading the entire signal. By selectively altering scale factors and Huffman codes in specific frequency bands, it provides protection while minimizing impact on overall audio quality.
Solution Approach 2:
The invention converts the potential harm of coefficient modification into a benefit by using perceptual audio models to identify which modifications will be least noticeable to human listeners. This transforms what could be quality degradation into an effective protection mechanism that is imperceptible to users.
3Reliability
If more information is transmitted for decoding protection, then security is improved, but the volume of information required increases
Solution Approach 1:
The patent extracts only the essential protection information by separating the modified coefficients from the main audio flux. Instead of transmitting additional protective data, it modifies existing coefficients in place, reducing the information volume required while maintaining security.
Data Source
AI summary
A process for distributing digital audio sequences according to a nominal flux format including a succession of fields, each of which includes at least one digital block clusterizing a selected number of coefficients corresponding to single audio elements that are digitally coded inside the flux and utilized by audio decoders that are able to play it to be able to decode it correctly, including a preparatory step including modifying at least one of the coefficients, and a transmission step including a primary flux in compliance with a nominal format including blocks that were modified during the preparatory step and by a route separated from the primary flux by an additional piece of digital information which allows reconstruction of the original flux starting with a calculation, on recipient equipment, as a function of the primary flux and of the additional information.