FT232rl USB Dongle - Page 1
Forum section: electronics / testgear

author: alaa77
author_rank: Newbie
timestamp: August 16, 2017, 07:15:14 am
content: FT232rl USB donglehiI want to use the FT232rl chip as a usb dongle based on the unique serial number.where they mentioned in the datasheet that it has a unique SN and ID.but I found that every body can change this serial number and Chip ID using the FT_Prog tool, so he can copy my SN to a new chip and break the security of my software.are there any solution to this problem?thanks

author: ataradov
author_rank: Super Contributor
timestamp: August 16, 2017, 07:39:31 am
content: Quote from: alaa77 on August 16, 2017, 07:15:14 amRethink your approach to security. It will take like 30 minutes to emulate any FTDI device on a general purpose MCU even if IDs were not changeable.You generally want to have at least request-response scheme. But even that is going to be hacked, if there is enough interest. That general purpose MCU will let you do this, and will be cheaper than FTDI anyway.

author: Rerouter
author_rank: Super Contributor
timestamp: August 16, 2017, 08:39:08 am
content: I would agree with challenge response,Most devices i have played with have switched to a full hardware dongle, but before that there where ones where the plugged in tool would only present a single HID, the program would issue its first challenge, respond, and then the micro would challenge, pc respond and it would wake up, and keep on doing this each minute.I know this because i ended up breaking the challenge / response so i could replace the software, but it was not easy because they where properly using the encryption functions of the micro they had. took a month of weekends. (developers had gone bust years ago)

author: alaa77
author_rank: Newbie
timestamp: August 16, 2017, 11:08:11 am
content: Quote from: ataradov on August 16, 2017, 07:39:31 amoh thanksI'm really interesting in using the MCU as a HID and build a dongle based on it.and I tried to use the "AVR MCU" to do that but didn't success.if there is any help it'll be great kind of you.alaa

author: Rerouter
author_rank: Super Contributor
timestamp: August 16, 2017, 11:31:34 am
content: If software is more your field than hardware, just buy one of the many available hardware dongle solutions, and structure your software around there implementations, if you prefer trying hardware, atleast start with a micro with native USB support, most will have HID examples.

author: alaa77
author_rank: Newbie
timestamp: August 17, 2017, 06:49:49 am
content: Quote from: Rerouter on August 16, 2017, 11:31:34 amYes I prefer trying hardware, and I built one with AVR microcontroller and FT232rl chip and it was ok.but I want to build as cheap as possible dongle so I tried to build one using just the FT232rl, but I found that it's not so safe!!!!!!!.so I think its good to try building a USB dongle using just an " AVR controller" as HID.here I'm asking for help.Thanks

author: ataradov
author_rank: Super Contributor
timestamp: August 17, 2017, 08:44:00 am
content: I have plenty of examples for SAM D11 on my GitHub. I'm on the phone at the moment, but links are easy to find.D11 is $1, cheaper than ftdi.