Answer:
The concealment cipher.
Explanation:
A concealment cipher also known as null cipher can be defined as an obsolete encryption format that typically involves the mixture of plaintext with non-cipher elements. This ultimately implies that, the plaintext is hidden in another message through encryption.
The concealment cipher is based on the clues of the physical factors, rather than the hardware or a software cryptosystem.
Basically, the concealment cipher is solely dependent on the clues of the physical factors that mainly affects the sender and receiver in a communication system.
The second one, it should be the one that is opening left with a line underneath, the images are unclear but that’s the most likely correct answer !
It takes places during surveying.
For example, let's say you want to review your own produced game application software, and found out whether it satisfy your consumer or not
Before you conduct the survey, you have to identify what aspect you want to find out from your consumers , such as : Does it have any bug ? Is it challenging enough ? is the graphic good enough ? etc
