USB stick shaped portable encryption device for basic encryption/messaging needs.
This is NOT a USB device. Do NOT plug into USB Port
This project is incomplete. Do not use. Do not trust. Do not do anything stupid or illegal. Have backups. Try on your own risk.
Even if you develop something useful, don't forget that there is no special protections and countermeasures for/against side-channel attacks, microprobing, emi/emc, tempest, power/clock glithing, freezing etc. Your application/device should take care about IV's and key loading.
I currently use PIC12F683 however, a new chip with hardware serial will skyrocket your project. Like 12F1840.