具有AES保密功能之多媒體小助手

Abstract

本論文中的系統是利用8051整合多媒體的應用，包括：MP3隨身聽，數位相機及錄音筆。其中MP3隨身聽多增加了六種情境模式提供使用者選擇，數位相機最大可支援VGA(640x480)格式，錄音功能可選擇16、24及32Kbps的儲存格式，所有的資料儲存於快閃記憶卡中，支援FAT12/16。此外韌體之中並加入AES（Advanced Encryption Standard）加密功能，可支援Nb=4，Nk=4(Nb為資料長度，Nk為金鑰長度)的資料保密格式，在論文中並提出一套利用兩把金鑰的方式，12 bytes從CF卡得到，4 bytes使用者輸入，來解決手持式系統輸入AES 16 bytes金鑰的問題。

The system proposed here integrates the functions of MP3 player, digital camera, and voice recorder, which are all controlled by 8051. The MP3 player supports not only normal functions but also six equalizer modes, the digital camera provides the VGA(640x480) format, and the voice recorder can store speech data with bit rate 16/24/32 Kbps. The MP3 and JPEG files can be saved to CompactFlash card with the format of FAT 12/16. Additionally, the Advanced Encryption Standard（AES）is introduced to keep stored data confidential. The system also supports the data encryption in the mode of Nb=4, the length of state, and Nk=4, the length of key. This thesis brings up an idea about how to enter 16-byte AES cipher key in a portable system by using two keys, where a 12-byte key is from the CompactFlash card, and a 4-byte key is provided by user.