Private communication systems have been around since the beginning of human culture. Many are still in use today and are used almost universally. My wife uses them to great effect. A discrete whisper in my ear while we are at a dinner table with friends, promising provocative events at home if we leave immediately, has many times caused me to manufacture some emergency that forces us to leave post haste.

Likewise, private hand signals and facial expressions at a crowded party signal the same promise and I thus act accordingly.

In business meetings, a gesture or some other private signal, or simply a notable statement from a random person might cause one of the participants to excuse themselves and talk privately outside.

Grave conviction

Private communications have saved my property, my businesses and even my life more times than I care to count. On my first trip to Kathmandu as a very young man I encountered a charming and charismatic Asian man who invited me on a private trip to Pokhara to visit his family homestead. His name, he said, was Charles Sobhraj. I was enthralled.

A gentleman sitting at the same restaurant overheard the conversation and when Charles left momentarily to visit the restroom, the gentleman leaned over and quietly said: "Do not go with this man. He will kill you and take your money." He looked me hard in the eyes, and then he leaned back and continued his meal. I was dumbfounded. The man spoke with such grave conviction that I declined Charles and quickly returned to my hotel. Sobhraj was arrested a year later and charged with the murder of dozens of foreign tourists. Look it up.

Most of my private communications have not had such dramatic consequences, but discrete whispers in my ear have more than once caused me to avoid situations that might have cost me my life. As to my property, including money, I could never have acquired or maintained what I have without, literally, tens of thousands private communications.

An invention not yet patented

A simple thing like an invention that has not yet been patented requires that as few people as possible know about it, and meetings between these people must be held in secure locations in absolute privacy. While developing the world's first software-based voice recognition system, which I later named "VoiceCommand", the developers and myself met in an abandoned warehouse in Santa Clara, California to work on the design and finalise the product.

I did not patent the product. I instead sold it to Interstate Voice Products in Southern California for what was at the time a small fortune. If someone had discovered the design early on by eavesdropping on these meetings, I might well have been pre-empted and all of my work would have been in vain.

So far I've only mentioned time-honoured means of private communications between people in the same room or in visual proximity. What happens when distance, in either time or space, is involved? Distance does not obviate the need for private communications. This is surely self-evident. But distance certainly complicates things.

With the advent of writing, a man could send en erotic message to his wife or private instructions to his business associates while on the Crusades, or was otherwise engaged, seal it with wax, and stamp his seal on it. If the seal was broken upon receipt, the messenger was summarily executed. This ensured a high degree of privacy.

Enticing suggestions

Today I use Chadder as my secure messaging app. Why? Because no one, and no agency can possibly, ever, break into it. I know you think I'm saying this because I had a hand in it. You are wrong. Time will prove it.

In any case my wife also uses Chadder, so that while she is getting her hair done in the town next door she can text me some enticing suggestions, sometimes quite graphic, that motivate me to stop what I'm doing and make sure the bedroom is in romantic order.

If these enticing suggestions were to be read by someone else the world probably would not come to an end. What my wife and I do behind closed doors is perfectly legal, at least in the State of Tennessee, and there would be limited repercussions. But my private business communications, and communications between myself and my lawyers, my bankers, my political affiliates, my spiritual counsellor, my product developers, my close friends, my doctors, etc. must absolutely be private, otherwise chaos would ensue.

In this age of communications that span both distance and time, the only tool we have that approximates a "whisper" is encryption. When I cannot whisper in my wife's ear or the ears of my business partners, and have to communicate electronically, then encryption is our tool to keep our secrets secret.

David Cameron in January said he wants to ban encryption to give the UK's security apparatus more access to messaging services such as WhatsApp, Facebook and iMessage. If encryption is banned , or if backdoors are put into encryption products, then, from sheer embarrassment alone, a communication channel between my wife and myself – a channel that many marriage counsellors deem vital to the health of a marriage - will be severed.

Can you imagine, then, the impact on the health and vitality of our world's commerce. And if encryption is thus controlled will we all require government's approval to whisper into the ears of our wives, friends and business associates? Will whisper auditor's be the next up and coming government occupation?

My wife just texted me. I must stop here.

Who is John McAfee?

John McAfee is one of the most influential commentators on cybersecurity anywhere in the world. His new venture – Future Tense Central – focuses on security and personal privacy-related products.

McAfee provides regular insight on global hacking scandals and internet surveillance, and has become a hugely controversial figure following his time in Belize, where he claims to have exposed corruption at the highest level before fleeing the country amid accusations of murder (the Belize government is currently not pursuing any accusations against him).