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 #### Secure Boot & Secure Firmware Update
 
-- [AVR230: DES Bootloader on tinyAVR and megaAVR devices](https://www.microchip.com/en-us/application-notes/avr230)
 - [AVR231: AES Bootloader](https://www.microchip.com/en-us/application-notes/an2462)
 - [Blinky To Bootloader: Bare Metal Programming Series (YouTube Playlist)](https://www.youtube.com/playlist?list=PLP29wDx6QmW7HaCrRydOnxcy8QmW0SNdQ)
 - [MOOC - Security Part4 : STM32 security in practice (YouTube Playlist)](https://youtube.com/playlist?list=PLnMKNibPkDnF0wt-ZI74SflnsBV4yKzkO)