By Charlotte Henry

As the mist of horror from the Westminster terror attacks began to clear, the assault on internet freedoms and online privacy began with depressing predictability.

Senior ministers who had responded so admirably to the attack last week suddenly took to the airwaves and newspaper pages to announce that it was in fact encrypted messaging service WhatsApp or Google that were the key to the problem. They said the end-to-end encryption which means only sender and receiver can see the message should be scaled back.

I understand, and try to empathise with, a minister's determination to do anything to reassure a concerned public, and to protect citizens. I do not think there is some cynical authoritarian motive at play here. If we've learned anything from the heroics of PC Keith Palmer, Tobias Ellwood MP, and the staff at St. Thomas' who ran towards the carnage on Westminster Bridge, it is that the overwhelming majority of people in public service want to do good.

However, we need to be clear. Attempts to break encryption on WhatsApp are dealing with the symptom, not the cause. The government is acutely aware that it needs to deal with radicalisation long before someone is about to commit an atrocity and mow down civilians, not when they may be sending a message mere moments before pulling the trigger.

If you ban or break encryption on WhatsApp there are plenty of other services where criminals of all stripes will go to communicate. Look through the App or Google play store, There are plenty of them quite legitimately out there, not to mention darker parts of the web where people can communicate without detection.

Banning WhatsApp or some of the technology it uses would just be playing Whack-a-Mole, waiting for the horrors to pop up, instead of doing anything substantive.

Former deputy prime minister Nick Clegg put it well in yesterday's Evening Standard:

"Intelligence agencies have long been in an arms race with technology. As I saw for myself in government, our agencies are extraordinarily smart at finding new covert technological solutions to new challenges. The solution isn't to try to turn the clock back; it’s to call on the ingenuity of the boffins at GCHQ."

He's right. The intelligence agencies do an extraordinary job in unfathomably difficult circumstances to protect us day-in, day-out. Indeed, the fact they are able to stop so many attacks in an environment where there is encryption suggests breaking it is not entirely necessary.

The suggestion to move away from end-to-end encryption also ignores quite how critical it is for businesses of all kinds in trying to prevent cyber attacks and fraud. It is critical to companies from the largest financial services firm to the smallest sole trader to protect their data, and allow them to conduct transactions in as safe a manner as possible.

If terror incidents happen or suspects are arrested, seizing phones and computers goes a long way to seeing their communication within a currently agreed legal framework. Yes it is difficult, but it does not violate the right to privacy of innocent civilians. Government does not need, and should not have, the right to simply pluck out of the ether any message we may send or receive.

We need encryption for lots of different reasons and these kneejerk reactions threaten our privacy, our economy and our civil liberties without substantially helping to protect us more.

Charlotte Henry is a commentator on technology, the media and politics. She hosts the Top Line podcast and blogs at charlotteahenry.com

The opinions in politics.co.uk's Comment and Analysis section are those of the author and are no reflection of the views of the website or its owners.