Encryption is nothing new: cryptographic messages that needed special tools to be decoded date back to ancient times. But the age of electronic communications and the widespread use of encrypted messaging apps has led to a new debate on the technology’s safety – and whether it should be allowed.
Encrypted communications are everywhere on the internet, from online banking to secure website connections to WhatsApp and iMessage. But the technology has also been criticised for allowing terrorists to communicate secretly, plotting attacks in safety that wouldn’t have been possible when they communicated by post or telephone.
What is encryption?
Fundamentally, encryption is the act of scrambling communication to stop people other than its intended recipient from reading it.
In various forms, the technique dates back millennia – Julius Caesar used basic encryption in messages to his generals – but modern warfare saw its use expanded. British codebreaking decryption of encrypted Nazi messages was seen as one of the defining moments in the war.
The Enigma machine used to encrypt Nazi communications CREDIT: PAUL GROVER
In the late 1960s the British intelligence organisation GCHQ started to develop the system of modern computer cryptography that is widely used today to secure online transactions and messages.
A decent analogy for encryption is the digital version of sending something in a locked safe. Only those with the right key can get in.
So what’s end-to-end encryption?
Encryption just means that communication is scrambled in some way. A message could still be encrypted and deciphered by the third party – a government or tech company – if they had a way to unlock it.
End-to-end encryption, on the other hand, means that a message is encoded in such a way that only the sender and receiver can see it.
To go back to the safe analogy, encryption simply means the safe is locked – someone with a key could get in. End-to-end encryption means nobody apart from the sender and receiver can open the safe.
Messaging apps such as WhatsApp and Signal now apply end-to-end encryption so that although messages may travel over their servers, they cannot read them even if they wanted to.
How does encryption work?
When you send a message to a recipient on WhatsApp, your app encodes it using a special key that can only be unlocked by the recipient. The actual process of encrypting the message is a complicated series of digital handshakes but all you need to know is that it is near-impossible to crack.
A fresh set of keys and locks is produced whenever two phones communicate, making the process safe each time.
Why is encryption important?
As we put more information online, including our photos, messages, financial transactions and other sensitive details, it becomes more important to stop people stealing them. Large attacks on companies such as Yahoo have shown the very real danger of personal details being leaked online.
Encryption is also seen as vital for people targeted by authoritarian states who could arrest and prosecute people for the information they share online – criticising the government or expressing religious or sexual freedom, for example.
What apps are encrypted and what aren’t?
Many messaging apps use encryption in some way, but end-to-end encryption is widely applied by WhatsApp, Signal and iMessage.
Facebook Messenger and Google’s Allo do offer end-to-end encryption, but not as default, while Telegram – which widely touts itself as a secure app – has been criticised over claims of security breaches.
Snapchat is not end-to-end encrypted. Messages are deleted from servers when they’re opened by recipients, but stored for 30 days if unopened. Text messages, which do not travel over data connections, are not encrypted.
Am I totally safe if I use encryption?
No. While someone snooping on a network or with access to a server won’t be able to read your messages, they can still be read on:
- Your screen
- The other person’s screen
- If you back chats up to the cloud.
If a phone is seized or cloud storage is accessed, you’re still vulnerable. This doesn’t make encryption a bad idea – it just isn’t foolproof.
Why is encryption controversial?
Governments say that security services need to be able to access people’s communications in extreme circumstances – when monitoring suspected terrorists or trying to gain information about a previous attack, for example. Adrian Ajao, the terrorist who killed four people in March’s Westminster attacks, sent a WhatsApp message just before the incident, for example.
Amber Rudd has attacked WhatsApp’s encryption CREDIT: REUTERS
Like the rest of us, criminals are using the internet more and more to plan and communicate, and authorities feel the rise of encryption is hampering their efforts.
While tech companies have been shown to work closely with security services in the past, end-to-end encryption means they themselves are unable to provide the contents of messages.
Why can’t an exception be made for police and terrorists?
End-to-end encryption means that there are no technical exceptions: even creating a bespoke way for security services to access communications would jeopardise the whole thing. To use the safe analogy once again, create one master key and you leave open the possibility that others could steal it or build their own.
Tech companies have used this as their main justification for refusing access. As Apple boss Tim Cook put it in 2015:
If you put a key under the mat for the cops, a burglar can find it, too. Criminals are using every technology tool at their disposal to hack into people’s accounts. If they know there’s a key hidden somewhere, they won’t stop until they find it
What is the UK Government doing about it?
Home Secretary Amber Rudd has criticised WhatsApp and other companies for limiting access to Ajao’s messages. MPs have also suggested that Donald Trump should put pressure on the American company.
It’s unclear exactly what this would achieve – end-to-end encryption means WhatsApp couldn’t help even if it wanted to – but pressure is likely to continue.
Last year’s Investigatory Powers Act does have a section that forces tech companies to break encryption in extreme circumstances. But how this would work in practice is unclear.
WhatsApp is unable to retrieve past messages without changing its entire system – something it is unlikely to do (and probably unable to do) for one country. If this were ever to happen, many people would probably just switch to another encrypted app.
More likely would simply be a UK-wide blackout on WhatsApp, which would be extremely unpopular. It has happened before in Brazil, to little effect.
This post was originally published on: Telegraph.
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