Encryption for IOT devices with minimal overhead I have several IOT devices that transmits nearly 200 bytes of data every 10 seconds. I want to make the data secured but i also want to keep the data size nearly same. Ofcourse for IOT devices computations should be lightweight. I have been considering AES 128 for this job and RSA for key exchange. I am wondering if i am on the right track or there are better options.

i saw NIST have called for lightweight encryption algorithm for IOT devices. until that is standardized which encryption should i use.

in summary, i want to get the overview of different encryption scheme with minimal overheads and computations. I looked around but there seems to be no this type of comparisons.

I am very much new in this field so forgive me if i have done any silly mistake.
For passively powered RFID tags, I settled on 160-bit ECC (Curve25519) to exchange the keys and SPECK for the actual encryption on a software platform.  If I make my own hardware, I use SIMON instead of SPECK.  For an IoT application, I see no reason not to do something similar.

If you are looking for comparisons of symmetric ciphers regarding throughput and power, I would suggest the SIMON and SPECK paper and the paper on PRESENT as both have good power tables and comparisons.