Dear Vijayh,

I suggest you to see links and attached file on topic.

The Direction of Lightweight Ciphers in Mobile Big Data Computing

https://www.sciencedirect.com/science/article/pii/.../pdf?md5...

Implementation of new hybrid lightweight cryptosystem - ScienceDirect

https://www.sciencedirect.com/science/article/.../S22108327173034...

FPGA Modeling and Optimization of a SIMON Lightweight Block Cipher

https://www.mdpi.com/1424-8220/19/4/913/pdf

Lightweight Block Ciphers for IoT: Energy Optimization and ...

https://ieeexplore.ieee.org/document/8387774

Best regards

Try the following paper:

https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=8387774

The block cypher itself gives raise to energy efficient algorithms. I would look at the associated algorithms (encryption, decryption).

Find the finite group algebra properties of the block cypher you use, that's where you can optimise.

Optimisation needs to consider two faces:

-authorised user

You want fast algorithms for encrypting and decrypting

-hacker/adversary

You want painful and lengthy algorithms as the only possibility for the adversary.

If your service is bidirectional, with say two people "talking" encryption and decryption might get the same weight in the optimisation criteria.

If your service is very asymmetrical, as in downloading or streaming movies or other contents, the weight is on the decryption (you encode once, you decode maybe millions of times)