Hierarchical encryption/decryption device and method thereof

Abstract

A hierarchical encryption device for decrypting a ciphertext and outputting a plaintext is disclosed in the invention, wherein the ciphertext comprises an encrypted block and a plurality of ciphertext blocks. The device comprises a first decryption unit, a generator and a second decryption unit. The second decryption unit is for decrypting the encrypted block by a secret key with a second decryption method to generate at least one index block and a plurality of confusion blocks. The generator is for generating a plurality of mask blocks according to the plurality of confusion blocks and the index block, wherein the number of the plurality of mask blocks is the same as that of the plurality of ciphertext blocks. The first decryption unit is for decrypting the plurality of ciphertext blocks by the plurality of mask blocks with a first decryption method to generate a plurality of plaintext blocks, wherein the number of the plurality of plaintext blocks is the same as that of the plurality of ciphertext blocks.

Description

technical field [0001] The present invention relates to the technical field of digital content data encryption and decryption systems and methods, in particular to the technical field of hierarchical digital content data encryption and decryption systems and methods. Background technique [0002] With the development of science and technology, digital content such as images, music, and videos have been widely used in various electronic devices such as computer devices, smart phones, and e-book readers, so as to provide users with different devices anytime, anywhere to read digital content. However, in the process of transmitting digital content, it is often necessary to further encrypt the digital content data to prevent improper use by others. [0003] At present, the encryption technology of general data information can be roughly divided into two categories, the first category is symmetric key encryption (Symmetric-key Encryption), and the second category is asymmetric ke...

AI Technical Summary

Problems solved by technology

Due to the more complicated calculation principle, asymmetric encryption system can provide quite high privacy and verification, but the disadvantage is that the calculation efficiency is poor, and it is usually used to encrypt data with a short length or digital signature. Symmetric key encryption standards include DSS, ECC, etc.

[0004] Due to the large capacity of digital content data files, many electronic devices use symmetric key encryption algorithms to encrypt and decrypt digital content, such as AES (Advanced Encryption Standard), 3DES ( Triple Data Encryption Standard) standard encryption and decryption algorithm, although it can provide secure data encryption protection for the entire digital content data file, relatively, when using software to calculate encryption and decryption algorithms such as AES and 3DES, it will consume quite a lot of computing resources and Time, especially on devices with low computing performance (such as handheld devices with ARM and Qualcomm processors), it takes a long time to encrypt and decrypt, causing inconvenience to users

The prior art proposes a solution, for example, using a dedicated hardware chip (ASIC, Application-specific Integrated Chip) on a device with low computing performance (such as a handheld device) to process encryption and decryption operations to speed up the processing speed and reduce processing time. It takes time, but its disadvantage is that additional dedicated hardware chips need to spend a higher cost

If you want to save costs without using dedicated hardware chips, in order to reduce the calculation time of encryption and decryption, another solution is to simplify the encryption and decryption algorithm. Although this method can reduce the time required for processing, it will reduce the security of digital content sex, it is not easy to achieve the purpose of preventing others from improperly using digital content

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