  In RSA cryptography numbers of the form $pq$, with $p$ and $q$ two distinct
proportional primes play an important role. For a fixed real number $r>1$ we
formalize this by saying that an integer $pq$ is an RSA-integer if $p$ and $q$
are primes satisfying $p<q\le rp$. Recently Dummit, Granville and Kisilevsky
showed that substantially more than a quarter of the odd integers of the form
$pq$ up to $x$, with $p, q$ both prime, satisfy $p\equiv q\equiv 3\pmod{4}$. In
this paper we investigate this phenomenon for RSA-integers. We establish an
analogue of a strong form of the prime number theorem with the logarithmic
integral replaced by a variant. From this we derive an asymptotic formula for
the number of RSA-integers $\le x$ which is much more precise than an earlier
one derived by Decker and Moree in 2008.
