Essential encryption

SIR – Last week’s attack in Westminster has reopened the debate on encryption, used by messaging services such as WhatsApp (“Internet giants hide terrorist’s final note”, report, March 27).

While this is understandable, it is important for our national security that we do not draw the wrong lessons from this tragic incident. It is unclear what role encryption played during the events last week. But we do know that strong end-to-end encryption plays a vital role in keeping our citizens, businesses and country safe.

As individuals, and as a nation, we benefit from strong encryption embedded into many of our digital devices and services – it is our most important defence from those who would wish us harm online. Strong encryption is binary. It exists or it doesn’t. So-called “back doors” will become open doors for cyber criminals, terrorists and hostile states. End-to-end encryption means there is no magic key to open messages.

But that doesn’t mean that nothing can be done. Tech companies working within the strict confines of the law go to great lengths to assist our security services. Such work is happening now. Meanwhile, the use of end-to-end encryption remains essential to keep the data and services we all rely on safe from online threats. Antony Walker Deputy CEO, techUK London EC4

SIR – Even if it were desirable for the Government to be able to decrypt WhatsApp messages, the difficulties are formidable.

The first is over who will hold the keys, and how messages will be accessed. WhatsApp is based in the US but available in any country whose citizens have internet access. Will a judge in the US have to decide each time police want to read messages?

Secondly, end-to-end encryption is a technology which any programmer can quickly learn. If WhatsApp handed over keys, this would be quickly known – and anybody who wanted encryption would move on to another platform or write their own software. Mark Wilce Amersham, Buckinghamshire