Maple has a software random() function for generating pseudo random numbers. Walter Anderson has developed an Entropy library for Arduino and ARM processors to use hardware timers and systick to generate stronger random numbers, see

https://sites.google.com/site/astudyofentropy/project-definition/timer-jitter-entropy-sources/entropy-library

As a proof of concept, I ported Walter's bit mixing functions into a maple sketch that uses the LSI clock and SYSTICK_BASE->CNT to generate random bits. The sketch which also uses the RTC lib is here

https://github.com/manitou48/DUEZoo/blob/master/maplerng.pde

A cursory analysis of a few megabytes of generated bits with diehard, rngtest, and ent, indicates the sketch provides "good" random bits.

Running the LSI clock at a 10-ms interrupt rate yields a random bit every 10 ms. The DUE hardware TRNG can generate 32 random bits every microsecond. Some other bit-generation rates are at

https://github.com/manitou48/DUEZoo/blob/master/RNGperf.txt