Final answer:
Implementing AES encryption on an Arduino to encrypt random words with different outputs involves manually coding the AES transformations and potentially using an initialization vector or a mode of operation like CBC to ensure randomness in the output. This requires advanced knowledge in embedded systems programming and cryptography.
Step-by-step explanation:
The question you've asked is related to implementing the Advanced Encryption Standard (AES) algorithm on an Arduino, and how to ensure that the encryption of random words yields different outputs each time. Writing such an encryption algorithm from scratch is a complex process that involves a deep understanding of cryptography and the ability to manage memory and processing constraints on an embedded system like the Arduino.
AES encryption uses symmetric key encryption where the same key is used for both encryption and decryption of data. It involves multiple rounds of four types of transformations: SubBytes, ShiftRows, MixColumns, and AddRoundKey. Doing this without calling an existing library means you will have to manually implement these transformations according to the specifications of AES.
To ensure that the output is different for each encryption of the same word (to add randomness), you would typically use an initialization vector (IV) or implement something akin to Cipher Block Chaining (CBC) mode or another mode of operation that includes an IV. All of this requires considerable work and a good grasp of embedded systems programming, as well as cryptography.