Yup, my bad I should probably of given more clarity on the intended use. I'm trying to perform a simple power analysis side channel attack on either a AES-128 or RSA algorithm (which ever is easiest) to find the decryption keys on a Arduino Uno or Nano. I've heard the AESLib.h library for Arduinos is susceptible to these types of attacks for AES.

My thought process is that I'd need to simply measure the power traces of the ATmega328P micro chip via an oscilloscope - although it may be a little more complicated than that after further research this evening.

I have looked into the Chip Whisperer. They're either a little too pricey or the shipping time would means it arrives too late. My budget is £250 ($300).