Quick enciphering method and device for wavelet image

Abstract

The present invention relates to method and device for safe information transmission. The quick enciphering device consists of DSP module, FLASH module, power supply managing module and clock module. The enciphering method includes: feeding pre-programmed cipher key via serial port to the enciphering device; feeding the image data flow to the enciphering device via the two-way channel comprising DSP serial port; analyzing the image into LF component and HF detail component; converting the wavelet coefficient of the LF component from floating point number into fixed point number; dividing the wavelet coefficient of the LF component into sub-groups of 128 bit; enciphering the sub-groups successively in AES algorithm; converting the wavelet coefficient of the LF component from fixed point number to floating point number; combining the wavelet coefficient of LF component and HF component to form compressed image file; and outputting the image data flow via the DSP serial port.

Description

technical field [0001] The invention relates to a method and device for safe transmission of information, especially an encryption method and a fast encryptor in safe transmission of image information. Background technique [0002] Due to the continuous improvement of computer computing power and the development of Internet-based distributed computing, it poses a huge threat to the DES algorithm with a key length of only 56 bits. Therefore, on April 15, 1997, the National Institute of Standards and Technology (NIST) launched Solicit activities for the Advanced Encryption Standard (AES) algorithm, and announced Rijndael on October 2, 2000 as a new generation of data encryption standards in the United States, aiming to protect the transmission of sensitive and non-confidential information of the government and other organizations. [0003] The Rijndael algorithm is an iterative block cipher with a data block length of 128 bits and a variable key length....

AI Technical Summary

Problems solved by technology

The general universal algorithm encrypts the code stream, the algorithm only requires the input of the binary bit stream, and does not care about the meaning of the bit stream; Make the implementation of the algorithm less efficient

[0005] But for multimedia information, especially image information, the traditional encryption technology encrypts it as an ordinary data stream without considering the characteristics of multimedia data, which has certain limitations.

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