xtea encryption

[toalan]

I just implemented xtea for the AVR MCU using C, it might be hard to implement in Picbasic since 32 bit unsigned long integers are not supported (I think).

I just copied from http://www.answers.com/topic/xtea into my C compiler (IAR embedded workbench)and was able to use it without modification for AVR.

xtea is supposed to be one of the most secure ( I do not think it has been cracked yet) and fastest algorithims. I looked into DES and AES and they seemed to time consuming to implement. I think xtea or one of its variants is used for the xbox.

I am using xtea to encrypt firmware so people can flash upgrade stuff without me worrying that they will steal my work.

[mister_e]

xtea is supposed to be one of the most secure ( I do not think it has been cracked yet)

LMAO well since you have a code and the explanation can be found somewhere... what is the big deal to crack something with it???

BTW all alrgorithm are still human made... another can bypass it easy... really easy

I think xtea or one of its variants is used for the xbox.

no comments, some are in jail now...

[toalan]

Sorry I am not following you, my implementation is to supply people with encrypted firmware, they send it to the MCU and the MCU will decrypt the data and write it to flash memory.

If you can bypass encryption easily then you are one of the few geniuses and perhaps your work has been undocumented. As of 2004 there is been no officially successful attempts at breaking the xtea algorithim.

The xtea algorithim in xbox was never really borken, people exploited flaws in the hardware design to run unsigned code, most notably the big font flaw.

[toalan]

if you guys are interested in my XTEA bootloader here it is http://www.14point7.com/AVR.htm

[Ron Marcus]

I will need to use encryption in a wireless stream for an upcoming product. XTEA looks good, and compact. I will write in assembly, but I wondered if anyone has played with this in PBP? It looks like a fun excercise, especially with the version 2.5 longs! Any other ideas for good encryption without a lot of overhead? It needs to stand up to that .01% of attacks.
Thanks,
Ron

[tenaja]

Go to the Swordfish Basic compiler site and download their demo program; it has XTEA with it. Surely you can convert it.
http://www.sfcompiler.co.uk/swordfish/