I am trying to understand some concepts regarding Random Read Access and Parallelism in mode of operations. I have written below what my concepts are regarding the two. If you can please correct where i am wrong, that would be great:
What is the difference between random read access and parallelism?
Ans: Random read refers to reading (decrypting) any nth block of data without calculating the previous n-1 blocks while parallelism is reading all or writing (encrypting) multiple blocks at the same time. Is that correct?
Random read access for decryption in general is good or bad?
Ans: It just adds convenience for the users at both ends.
Has random read access got any security implications if its possible in a particular mode of operation. For instance, CBC that allows random read access. Is it easier for an attacker to read any specific block he wants? Or it doesnt matter because the attacker can decrypt all or one block he/she wants.
I am not sure about this one