Oscar wants to send a message $\backslash ($ M $\backslash )$ to Bob claiming it is coming from Alice. Oscar knows the public parameters of Alice's RSA digital signature: $\backslash (($e$=17,$ n$=2257)\backslash ).$ Oscar also wants to use EMSA$-$PSS padding:

$\backslash [$

$\backslash$begin$\{$array$\}\{$c$\}$

D B$=\backslash \backslash$

E M$=$

$\backslash$end$\{$array$\}$

$\backslash ]$

$($a$)$ What is the key value Oscar uses to generate the signature?

$($b$)$ What does Oscar send to Bob?

$($c$)$ Describe the verification process step$-$by$-$step that $\backslash ($ B o b $\backslash )$ has to perform to verify the received message. $[$Note that after completing the verification, $\backslash ($ B o b $\backslash )$ will be convinced that the message he received was created by Alice, even though it was, in fact, generated by Oscar.$]$