Tin cans and a string
The issue isn't network security it's communications security. As soon as some form of relay is established, security is compromised and one faces tradeoffs.
Does one send a single messenger on horseback (slower, less conspicuous but more vulnerable), surround the messenger with armed guards for protection (slower, more expensive, more conspicuous, less vulnerable) or presume monitoring but encode like smoke signals (conspicuous, faster, decipherable)?
Technology has made the means of communication orders of magnitude more complex but the same basic trade-offs haven't changed. What technology has also done has increased the number of domains and instances of messages categorized as needing to be secure. No longer is security just the provenance of battlefield communication.
For some reason there is a growing acceptance that loss of privacy for individuals is inevitable but what hasn't yet caught on is that privacy for abstract entities such as governments, corporations etc. will also be eroded.
Right now, people accept cameras everywhere monitoring our behavior but institutions are allowed to go about much of their business without such constant monitoring. We can't Imagine that there would ever be cameras in every board room, every court, every meeting. What would be the effect of such transparency ? And yet this transparency is happening not with cameras but with every form of communication within institutions and they don't like it.
People think monitoring is fine when they think they have nothing to hide but does refusal to be monitored mean there is something to hide? Institutions give reasons such as state security, competitive advantage, protection of property, the recently conjured up modern notion of privacy etc.. but if individual privacy is eroded one can't expect institutional privacy to be maintained.
Technology is neither the problem nor the solution. It is rooted in our very attitudes towards others. Competition, mistrust, domination and unifying conceptions which tend to be exclusionary and limited (religion, nationalism, gardening and fan clubs are all examples).
We are dealing with two contradictory principles that have been used to describe our "information age", one that information is power and the other being information wants to be free.
Although as in times past, increasing amounts of money, time, effort and technology will be thrown at this security problem, we can neither get off this road nor know where it is taking us but there will be much "sound and fury" along the way.