Network transmission method for digital orthophoto maps

Abstract

The invention discloses a network transmission method for digital orthophoto maps. The method includes selecting, by a sending terminal, a transmission file; reading the start address and length of the key data of the file; reading the start address and length of the image data area of the file; writing all the read start addresses and byte numbers in an encryption document; reading the content ofthe key data to write in the encryption document, and setting the key data as zero; judging an encryption grade; selecting, by the sending terminal, a control point outcome table to generate an encrypted cipher suite; encrypting all data in the encryption document except the start addresses, the byte numbers and control point numbers; transmitting the zero setting file and the encryption documentto a receiving terminal; generating, by the receiving terminal, an encrypted cipher by using the control point outcome table; decrypting, by the receiving terminal, the encryption document by utilizing the encrypted cipher; and writing the contents of the decrypted encryption document in the zero setting file according to corresponding addresses so that an original digital orthophoto map file canbe obtained. The beneficial effects of the method are that the method is fast in transmission speed, high in confidentiality, controllable in confidentiality level, and convenient in usage and secretkey generation.

Description

technical field [0001] The invention relates to the fields of surveying and mapping technology and information security technology, in particular to a method for network transmission of a digital orthophoto map. Background technique [0002] In pipeline construction, especially in the stages of pre-feasibility study, preliminary design and construction drawings, it is often encountered that the transmission of orthophoto maps of a confidential scale contains national coordinates. Data, drawings, and image maps involving point coordinates of important engineering facilities of the national economy with an accuracy better than ±100 meters are relatively common, especially the stations, valve rooms, crossing points, tunnels, and national strategic reserves of the national trunk oil and gas pipeline network Transmission of digital orthophoto maps is more common. In addition, in the construction of projects, especially the construction of national key projects, surveying and map...

AI Technical Summary

Problems solved by technology

[0003] The above-mentioned data cannot be transmitted on the Internet, and the main method currently used is manual acquisition and transmission

The disadvantage of this transmission method is that the transmission speed is slow, the cost is high, real-time transmission cannot be realized, and files are prone to loss, damage, theft and leakage, and it cannot meet the needs of intelligent construction

There are also methods such as compression, adding fixed passwords, and using some encryption algorithms. This method belongs to the packaging of confidential documents and is easy to be cracked and leaked.

There is also a method of directly replacing the file name without any change in the content, which is the least confidential

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