Method for calibrating integrity of P2P download files

Abstract

The invention relates to a method for calibrating integrity of P2P download files. The method comprises the following steps: dividing file blocks into sub data blocks according to characteristic parameters of a download client; when receiving a sub data block, calculating a Hash abstract of the sub block by using Hash algorithm and updating Hash vectors of a new file block; when downloading and calculating Hash values of last sub block, generating Hash values of file block immediately; and hiding delay of integrity calibration of files during download process. The invention uses a TCP asynchronous receiving buffer region so that delay of calibration during P2P download process can be hidden completely, the efficiency of P2P download is improved effectively, especially the efficiency of P2Pdownload on an embedded platform is improved. Furthermore, the invention is independent from specific calibration frame or protocol. Specially, core thought of the method can be applied directly to prior P2P download protocol, for instance eMule protocol and BitTorrent protocol, which has greater practicability.

Description

technical field [0001] The invention relates to the field of network communication P2P data distribution, in particular to a method for verifying the integrity of P2P downloaded files. Background technique [0002] P2P downloading is the main way of Internet file downloading at present. Unlike the traditional C / S mode, the data downloaded by P2P comes from many different nodes, and there is no way to ensure that all nodes are credible, so the downloaded files must be completely checked. sex check. The current mainstream P2P download protocols, such as eMule and BitTorrent, mostly divide a file into different file blocks. After each complete file block is downloaded, it uses MD4 or SHA1 hash algorithm for integrity verification, so that Quickly locate erroneous file blocks, thereby ensuring the integrity of the entire file. [0003] For a specific platform, the size of the TCP asynchronous receive buffer and the ability to calculate the hash are usually fixed. At the same ...

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Problems solved by technology

[0005] 2) Transmission time overhead

However, on the one hand, opening a new thread to perform file integrity verification will increase the complexity of the system software; on the other hand, during the P2P download process, nodes need to download data from multiple partner nodes at the same time, which will lead to opening too many threads. May increase system overhead and reduce efficiency

Some literatures combine their proposed verification framework and protocol to propose a block-based probabilistic verification algorithm. The idea is to selectively verify some file blocks to reduce the computational overhead in the entire file integrity verification process. Missed detection cannot be completely avoided, so it is not suitable for file downloads with high reliability requirements

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