Multimedia File Encryption Structure for Random Access

Solution Overview

Problem

Conventional encryption methods for digital content data, which encrypt data block-wise from head to end, lead to inefficient access processing times when trying to access specific positions, particularly affecting portable devices by increasing power consumption and reducing continuous use time, especially for functions like fast-forward, rewind, and random access in multimedia content.

Innovation Solution

A data structure and method for encrypting multimedia files that stores non-encrypted size and type fields for boxes, allowing efficient access by encrypting only the multimedia data and information data within boxes, while keeping size and type fields unencrypted, enabling direct access without sequential decryption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If content data is encrypted in block from head to end, then copyright protection is improved, but access processing time to optional positions deteriorates

Engineering Contradiction:

Improvecopyright protectionVSAvoidaccess processing time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The content data is divided into multiple blocks, with the head block containing unencrypted metadata (size, type fields) and encrypted content data, and subsequent blocks containing only encrypted content data. This segmentation allows the system to maintain copyright protection through encryption while enabling efficient random access by reading unencrypted metadata to locate specific positions without decrypting the entire file.

Inventive Principle:

Principle #1Segmentation

2Reliability

If content data is encrypted in block from head to end, then copyright protection is improved, but power consumption increases

Engineering Contradiction:

Improvecopyright protectionVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The content data is divided into multiple blocks, with the head block containing unencrypted metadata (size, type fields) and encrypted content data, and subsequent blocks containing only encrypted content data. This segmentation allows the system to maintain copyright protection through encryption while enabling efficient random access by reading unencrypted metadata to locate specific positions without decrypting the entire file.

Inventive Principle:

Principle #1Segmentation

3Reliability

If content data is encrypted in block from head to end, then copyright protection is improved, but processing load increases

Engineering Contradiction:

Improvecopyright protectionVSAvoidprocessing load

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The content data is divided into multiple blocks, with the head block containing unencrypted metadata (size, type fields) and encrypted content data, and subsequent blocks containing only encrypted content data. This segmentation allows the system to maintain copyright protection through encryption while enabling efficient random access by reading unencrypted metadata to locate specific positions without decrypting the entire file.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS8214655B2Data structure of multimedia file format, encrypting method and device thereof, and decrypting method and device thereof

Publication Date: 2012.07.03 KK TOSHIBA

AI summary

In a data structure of a multimedia file format, a movie box and a media data box are provided. In each box, a non-encrypted size field, a non-encrypted type field and box data field are provided. In box data of the movie box, information data regarding multimedia data is stored. The multimedia data is encrypted and stored in box data of the media data box. The information data is obtained by referring to the container in the movie box. This information data is held as encryption and encoding information data. By referring to the information data, a data unit of the encrypted multimedia data in the media data box is obtained, and the unit data is decrypted.