If \fBtrue\fR (the default) then check if \fIp\fR is prime.
.PP
A \fIdh closure\fR defines a group to be used for key exchange.
If \fBtrue\fR (the default) then check if \fIp\fR is prime.
.PP
A \fIdh closure\fR defines a group to be used for key exchange.