Is there any AES128 arduino library for arduino due for encrypting strings.
Tried many examples,but no use.
There are many libraries and encryption algorythm types, you can search them in this forum and also in Github.
I tried the following library: new AES library - Libraries - Arduino Forum
I was able to get the same result using the above posted New AES library and the openssl command in linux. For me it was a time consuming experience because you need to learn and get some technical background, for example the different Mode of Operation used in block ciphers (Block cipher mode of operation - Wikipedia).
I don know your technical background, but I can help you with the openssl command parameter I used to get the same result as the Arduino library.
Good luck!