Consider the following MAC $=($Gen$,$ Mac, Vrfy$)$ for messages of length

l $($n$)=2$n $2$ using a PRF f : $\{0,1\}^$n $\{0,1\}^$n $\{0,1\}^$n$.$

$$ Gen: Selects a key uniformly at random from k in $\{0,1\}^$n

$$ Mac: on input m$0$ m$1($with $|$m$0|=|$m$1|=$ n $1)$ and key k in $\{0,1\}^$n$,$ output

t:$=$ fk $(0$ m$0)$ fk $(1$ m$1)$

$$ Vrfy: on input m$0$ m$1($with $|$m$0|=|$m$1|=$ n $1),$ key k in $\{0,1\}^$n and tag t compute Mack $($m$0$ m$1)$ and compare the result to t$.$ If they match, output $1$;

otherwise output $0.$

Is $$ forge secure$?$ Prove your answer.