Arduino Encryption

I've been looking at encryption libraries that would run on an Arduino.  This looks like something worth looking into.

This library contains a cryptographic pseudo-random number generator, cryptographic hash and message authentication code (MAC) functions, can perform symmetric-key authenticated data encryption, and general-purpose functions for timing-safe comparison and wiping data from memory.

https://hackaday.io/project/8244-arduino-spritz-cipher-library
https://github.com/abderraouf-adjal/ArduinoSpritzCipher
https://people.csail.mit.edu/rivest/pubs/RS14.pdf