# XTEA brute force 128 bits key, 64 rounds

Is my calculation correct that to bruteforce XTEA with 128 bit key:

https://www.wolframalpha.com/input/?i=number+of+4-permutations+of+4,294,967,295+objects

Would require that many permutations?

Are there any attacks known to bruteforce it or decrypt? Especially in context of RKE (Remote Key Entry)

Thanks,

• @android_dev Not quite as you can also permute within the objects (int) too. Simply think of it as a wide counter from 0 to $2^{128} -1$. – Paul Uszak Jan 19 '19 at 13:22