Note: the following comment is based as my experience as an engineering officer in the RAAF, with cryptographic clearance (someone has to load the keys into the

Note: the following comment is based as my experience as an engineering officer in the RAAF, with cryptographic clearance (someone has to load the keys into the crypto devices!). Yes, as anyone that has ever had a security clearance knows, the biggest target of humint is sigint. The level of clearance that is needed to handle cryptographic material is higher than the clearance to know about the information sent by the cryptographic system. That's because one piece of information, no matter how sensitive, is nowhere near as damaging as being able to read all encrypted material of your enemy. Clearances aren't just a title that you get - an increase in your security clearance goes hand in hand with your history coming under heavier scrutiny. At first you might just get a cursory check to verify that you are who you say you are - teachers from your school may be contacted, neighbours etc. As you start gaining access to cryptographic networks, the checks start going into who you associate with, what your hobbies are, what's happening in your bank account. And the checks get more discreet - you might learn about your primary school teacher getting asked questions about you, but you won't learn that your telephone conversations were listened to for 6 months to make sure you're not hanging out with $THREAT_DU_JOUR. So if sigint is valuable, one of the best ways to get your hands on it is to compromise someone that has access - in other words humint. The two are not disassociable.