The likelihood of them ever having the cryptographic components of ScreenOS competently audited is very low.
Most firms didn't even start getting basic software security assessments done until ~5 years ago, and almost nobody gets crypto reviews done (crypto reviews are nosebleed expensive, because only a tiny fraction of software security people can do them competently).
Most firms didn't even start getting basic software security assessments done until ~5 years ago, and almost nobody gets crypto reviews done (crypto reviews are nosebleed expensive, because only a tiny fraction of software security people can do them competently).