Ultra-high-definition digital media content distribution method and system based on fragmentation encryption and dynamic caching

Abstract

The invention discloses an ultra-high-definition digital media content distribution method and system based on fragmentation encryption and dynamic caching, and belongs to the technical field of digital media transmission and content distribution. The method comprises the following steps: encrypting an ultra-high-definition media master file, embedding a digital watermark bound with a terminal identity, and then segmenting the file into a plurality of encrypted fragments; the content popularity index is calculated through a metadata server, and the distribution and retention time of encrypted fragments in edge cache nodes are dynamically managed based on popularity, so that hot contents are widely cached, and cold contents are automatically recycled; and the authorized playing terminal downloads the encrypted fragments from a plurality of edge nodes in parallel, and completes decryption, watermark verification, recombination and playing in a local hardware security module or a trusted execution environment. According to the method, the optimal balance of safety, efficiency and cost in the ultra-high-definition content distribution process is realized, and the method has the advantages of full-chain copyright protection, flexible resource scheduling and high-quality playing experience.

Description

Technical Field

[0002] This invention relates to the fields of digital media transmission, content distribution networks, and digital rights management technology. Specifically, it relates to a secure, efficient, and low-cost distribution method and system for ultra-high resolution digital media master files such as 4K / 8K, which is particularly suitable for scenarios with extremely high requirements for content security and quality, such as theatrical releases and high-end streaming media. Background Technology

[0003] Ultra-high definition (UHD) video content, such as 4K / 8K master files, typically ranges in size from tens to hundreds of gigabytes. Traditional content distribution methods face the following main challenges: Distribution costs are high: transmitting a complete, ultra-large file at once via satellite link or private network consumes a huge amount of bandwidth and incurs high time and monetary costs, making it difficult to quickly achieve large-scale simultaneous release.

[0004] The risk of copyright breaches is severe: Current content delivery networks typically cache complete media files in plaintext or simple encryption on edge servers. Once an edge node is compromised, the entire media content faces the risk of being leaked at its source, becoming a significant source of piracy.

[0005] Rigid caching strategies lead to low resource utilization: Film and television content has significant lifecycle characteristics (peak season, off-season). Static "full cache" or "full origin cache" strategies cannot adapt to this change: during peak season, insufficient caching may affect the playback experience; after the film ends, a large amount of marginal storage space is ineffectively occupied, resulting in resource waste.

[0006] While existing CDN-based distribution solutions can accelerate delivery, they lack deep adaptation to the specific characteristics of ultra-high-definition content, particularly in terms of dynamically balancing security and cost. Traditional DRM technologies focus on end-to-end transmission encryption, paying insufficient attention to content protection within edge caching nodes and intelligent resource scheduling based on content lifecycle. Summary of the Invention

[0007] The present invention aims to solve the above-mentioned technical problems and provide an ultra-high-definition content distribution solution that takes into account security, efficiency and economy.

[0008] The core of this invention lies in the combination of the following unique technical features: Segmented encryption with integrated digital watermarking: During the encryption and segmentation of ultra-high-definition media files, a digital watermark bound to the identity information of the authorized playback terminal is selectively embedded in specific segments or all segments. This watermark remains after the content is decrypted and reassembled, and can be used for tracing piracy, greatly enhancing copyright protection capabilities.

[0009] Dynamic caching strategy based on content popularity: The system has a metadata server that continuously tracks and calculates the real-time popularity index of each piece of content (based on factors such as subscription request frequency, play count, and release time). The scheduling system dynamically adjusts the cache distribution and retention time of content segments on edge nodes based on this popularity index: popular content is widely pre-promoted or retained on edge nodes at various levels; after popularity declines, segments are automatically reclaimed or cleared from edge nodes, remaining only in the central secure archive.

[0010] Terminal hardware-level security protection: The authorized playback terminal is a dedicated broadcast control server or hardware player. Its core decryption, watermark extraction and verification, segmentation and synthesis and decoding playback modules run in a hardware security module or trusted execution environment to ensure that sensitive information such as private keys and plaintext content are not exposed in the general operating system environment.

[0011] The beneficial effects of this invention are: Significantly reduced distribution costs: By utilizing the segmented parallel download mechanism, the system makes full use of internet bandwidth, reduces reliance on expensive dedicated lines or satellite links, and shortens the deployment time for simultaneous global release of content.

[0012] Building a full-chain copyright protection system: Combining "fragmented encryption to prevent leakage", "embedded digital watermarking for traceability" and "terminal hardware anti-hacking" triple protection, it achieves full-chain security control from distribution center, transmission network, edge caching to final playback.

[0013] Achieving elastic and intelligent resource utilization: Dynamic caching strategies enable storage resources to be allocated in close accordance with the commercial value curve of content, expanding when hot and shrinking when cold, greatly improving the return on investment of edge infrastructure.

[0014] Ensuring a high-quality playback experience: Intelligent scheduling ensures that popular content can obtain segments from the nearest and fastest edge nodes, effectively reducing initial loading latency and playback stuttering. Attached Figure Description

[0015] Figure 1 : A schematic diagram of the system architecture and data flow provided in an embodiment of the present invention.

[0016] Figure 2 : A schematic diagram of the dynamic caching strategy logic provided in an embodiment of the present invention. Detailed Implementation

[0017] System Architecture: like Figure 1 As shown, the system mainly includes: Central Production and Distribution Server: Responsible for preprocessing ultra-high-definition master files, embedding basic copyright information, performing encryption and fragmentation operations, and managing content metadata and popularity index.

[0018] Intelligent scheduling and metadata server: responsible for maintaining the status of global edge nodes, storing shard indexes, calculating content popularity, and dynamically issuing caching instructions according to policies.

[0019] Distributed edge cache node network: CDN nodes or cinema local servers deployed in various geographical locations to store encrypted video clips. Their cached content is dynamically managed by the scheduling system.

[0020] Authorized playback terminals, such as cinema digital movie servers and high-end home media players, have built-in security hardware for requesting, downloading, decrypting, reassembling, and playing content.

[0021] Method and Flow: like Figure 1 As shown, taking the entire lifecycle of a film from its release to its screening and eventual removal from theaters as an example, the method includes the following steps:

[0022] S101: The central server retrieves an 80GB 4K movie master file.

[0023] S102: Generate watermark information that is linked to each authorized cinema or region according to the distribution plan.

[0024] S103: Encrypt the master file and embed watermark information into the data fragments during or before fragmentation after encryption. One approach is to distribute the watermark across specific locations in multiple fragments.

[0025] S104: Divide the watermarked encrypted file into N data fragments.

[0026] S105: In the initial stage, based on the release schedule (e.g., one week before release), all pre-release promotional content will be pushed to edge caching nodes in core cities across the country (e.g., the top 100 cities). The scheduling server will set the content's popularity index to "Pre-release - High".

[0027] S201: A cinema in City A has ordered the film, and its broadcast control server (terminal) sends a playback request to the scheduling server.

[0028] S202: The scheduling server generates an optimal segment download list for the cinema in City A based on the cinema's location, network conditions, and the current segment caching status of each edge node (for example, segments 1-30 are downloaded from the local node in City A, and segments 31-80 are downloaded from the neighboring node in City B).

[0029] S203: The cinema broadcast control server downloads the required encrypted segments in parallel from multiple specified edge nodes.

[0030] S204: After all fragments are downloaded to the terminal, they are decrypted within the Hardware Security Module (HSM) or Trusted Execution Environment (TEE) inside the terminal. This security environment is also responsible for verifying the consistency between the watermark information and the terminal's identity.

[0031] S205: Within a secure environment, the decrypted fragments are reassembled into a complete media file stream, which is then directly sent to the decoder for playback. Throughout the entire process, the complete plaintext content is never exposed outside the terminal's secure hardware.

[0032] like Figure 2 As shown, this process runs in parallel with S2 and is continuously executed by the scheduling system: S301: The metadata server collects request metrics for each piece of content in real time, calculates and updates its popularity index. For example, during the first week of release, the request volume is huge, and the popularity is "extremely high"; after a month of release, the request volume decreases, and the popularity drops to "medium"; after the film leaves theaters, there are only sporadic views, and the popularity is "low".

[0033] S302: The scheduling system executes caching actions according to a preset strategy. "Extremely high heat": The instruction replicates all fragments to the more peripheral edge nodes as much as possible.

[0034] "Medium" popularity: Shards are reclaimed from some low-traffic peripheral nodes, but retained in the regional core nodes.

[0035] Low popularity or content being taken off the air: Triggers an automatic recycling and cleanup process, removing all segments from all edge cache nodes, retaining only the encrypted master in the central archive. Storage space is freed up for new popular content.

[0036] Example: An 80GB 4K movie is planned for global release. The distributor uses the method described in this invention to pre-warm encrypted video clips to edge nodes in major cities worldwide one week before the release. When a cinema in City A orders a screening, the clips are retrieved in parallel from nodes in its city and neighboring cities. Decryption, watermark verification, reconstruction, and playback are then performed by a security module built into the cinema's server's HSM (Hardware Storage Management System). During the movie's run, high demand leads to extensive caching of the clips. After the run, the scheduling system automatically removes all clips from the global edge nodes, saving over 95% of edge storage space and completely eliminating the risk of data leakage that could arise from long-term storage on edge nodes.

Claims

1. A method for ultra-high definition digital media content distribution based on sharding encryption and dynamic caching, characterized in that, The method comprises the following steps: A security fragmentation and marking step: encrypting the ultra-high-definition digital media master file, embedding a digital watermark in the encryption or fragmentation process, and then cutting the file into multiple encrypted fragments; the digital watermark is associated with the identity information of the authorized playback terminal; An intelligent distribution and caching step: storing the encrypted fragments in a central server and multiple distributed edge cache nodes; A metadata server dynamically manages the distribution and retention of fragments in edge cache nodes according to the heat index of the content, wherein the fragments of high-heat content are widely cached or pre-pushed to edge nodes, and the fragments of low-heat content are recovered from edge nodes; A terminal secure playback step: the authorized playback terminal obtains fragment location information from the scheduling server when playback is needed, and downloads the required encrypted fragments from multiple edge cache nodes in parallel; in the hardware security module or trusted execution environment locally on the terminal, the downloaded fragments are decrypted, the watermark is verified, and the complete media stream is reassembled for playback.

2. The method of claim 1, wherein, The "embedding a digital watermark" specifically refers to dispersively embedding a digital watermark representing the unique identity of the terminal or authorized license information into multiple or all data fragments through encoding.

3. The method of claim 1, wherein, The calculation of the "heat index" is based on one or more of the following factors: the number of content playback requests per unit time, the release life stage of the content, and the number of content subscriptions.

4. The method of claim 1, wherein, The "dynamically managing the distribution and retention of fragments in edge cache nodes" specifically includes: when the heat index is lower than a preset threshold, the scheduling system automatically sends instructions to the edge cache nodes to delete all encrypted fragments of the specified content.

5. The method of claim 1, wherein, In the terminal secure playback step, the hardware security module or trusted execution environment is also used to verify whether the digital watermark carried by the decrypted fragments matches the terminal's own identity information, and the playback process is aborted if the verification fails.

6. A system for implementing the method of any one of claims 1-5, characterized by The method comprises: A central production and distribution server configured to perform encryption, digital watermark embedding, fragmentation, and heat metadata initialization of media files; An intelligent scheduling and metadata server configured to calculate and update content heat indexes, dynamically manage fragment storage in edge cache nodes according to heat index strategies, and provide fragment scheduling information in response to terminal requests; Multiple distributed edge cache nodes configured to store encrypted fragments and execute cache, retention, or deletion instructions from the scheduling server; At least one authorized playback terminal with a built-in hardware security module or trusted execution environment configured to download fragments according to scheduling information and complete decryption, watermark verification, reassembly, and playback in a secure environment.

7. The system of claim 6, wherein, The authorized playback terminal is a digital cinema server or a dedicated hardware player.

8. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the program to implement the steps of the method of any one of claims 1-5.

9. A computer readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to implement the steps of the method of any one of claims 1-5.

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