Apparatus for encrypting/decrypting real-time input stream

Abstract

Disclosed is an apparatus for encrypting/decrypting a real-time input stream. The present invention includes a control unit, a key schedule unit, and a block round unit. Accordingly, the present invention realizes the encryption and decryption of AES algorithm in a manner of hardware, thereby enabling to carry out the encryption and decryption of the real-time input stream real-timely. And, the present invention finds the key for encryption or decryption of one block every round when realizing the encryption and decryption of the AES algorithm in a hardware manner, and then outputs the found keys to the block round unit. The present invention reduces the size of the key register required for the encryption/decryption of block data, thereby enabling to reduce a size of hardware as well as cost of product.

Description

CROSS REFERENCE TO RELATED ART [0001] This application claims the benefit of Korean Patent Application No. 2001-2644, filed on Jan. 17, 2001, which is hereby incorporated by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to an apparatus for encrypting / decrypting a real-time input stream using AES (Advanced Encryption Standards) algorithm. [0004] 2. Background of the Related Art [0005] As importance of pay information and privacy protection increases, so does that of encryption / decryption apparatuses. Specifically, the next generation encryption standards have been newly proposed so as to replace the DES (Data Encryption Standards) which has been the U.S. encryption standard. [0006] NIST (National Institute of Standards and Technology) has evaluated 15 algorithms as AES candidate technologies for years, and has narrowed the candidates to 5 and has finally selected the Rijndael algorithm as the next generation encryption st...

AI Technical Summary

Benefits of technology

[0010] An object of the present invention is to provide an apparatus for encrypting / decrypting a real-time input stream enabling to encrypt and decrypt a real-time inputted stream real-timely by constructing Rijndael algorithm selected as AES algorithm with hardware.

[0011] Another object of the present invention is to provide an apparatus for encrypting / decrypting a real-time input stream enabling to carry out encryption and decryption with a simple hardware structure by sharing a block used in common when realizing hardware of Rijndael algorithm.

Problems solved by technology

Yet, the AES algorithm introduced by software fails to carry out encryption / decryption for a real-time input stream.

However, the block round in the AES algorithm constructed with software fails to fulfill such operation.

Thus, when consecutive data streams are inputted, the block round with software is unable to secure a time to perform a processing on data by preparing one block, thereby failing to carry out the real-time processing on the consecutive data streams.

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