We explain how to send sensitive information via email and messenger app. How to send secure emails, how to send secure messages. (See also: 5 of the best ways to send large files for free: share videos and other email-busting documents.)

How to send secure emails

To properly secure email messages you need to encrypt two things: the connection from your email provider, and the email itself. The first stops messages being probed as they send, encrypting the email itself means that any intercept will be foiled.

First we'll secure the connection between your email provider and your computer. You need to set up Secure Socket Layer (SSL) and Transport Layer Security (TLS) encryption.

If you use the internet to check your email check that SSL/TLS encryption is active. If it is, the website address (URL) will begin with https instead of http. If you don't see an 'https' address type an s at the end of the 'http' and press Enter. This will usually prompt your email provider to encrypt your connection.

If you use a desktop email client such as Outlook or Thunderbird, or a smartphone or tablet with an email app, encryption is harder to verify or to set up. Open up the app or software and navigate to the settings menu. Then in the advanced settings near where you can specify the port numbers for incoming and outgoing connections look for an option to activate encryption.

Now we will encrypt individual email messages during transit. This is a lot more involved and will mean both you and your email recipient must do some work ahead of time. It's probably best to save this for extreme circumstances.

Fortunately you can usually use the built-in encryption features provided by your email service (see also: Use Outlook.com's aliases to hide your true email address from prying eyes). Failing that you can download encryption software or client add-ons. And if all else fails you can use a web-based encryption email service such as Sendinc or JumbleMe.

Message encryption protocols such as S/MIM and OpenPGP require you to install a security certificate on your computer. You then give trusted contacts a string of characters to use as a key before they can send or receive an encrypted message with you. Likewise, the intended recipients of your encrypted message must install a security certificate on their computer and give you their public key in advance.

Support for the S/MIME standard is built into many email clients, including Microsoft Outlook and Thunderbird. If you use webmail browser add-ons such as Gmail S/MIME for Firefox do the job. To get started, you need to apply for a security certificate from a company such as Comodo.

The OpenPGP (Pretty Good Privacy) email encryption standard has a few variants, including PGP and GNU Privacy Guard (GnuPG). You can find free and commercial software and add-ons, such as Gpg4win or PGP Desktop Email, that support the OpenPGP type of encryption. More here: How to encrypt your email.

(See also: Back up and restore your PC's Windows Registry; secure your PC- or laptop's Registry.)

How to send secure messages

PQChat IIIWe are, however, using email less. Instant Messaging has become incredibly popular with apps such as WhatsApp offering a free way to send messages across the web. Messenger apps such as WhatsApp are great, but I wouldn't be comfortable sending sensitive data such as my band details in such a way. There is a solution, however.

It's a service called PQChat. Similar to WhatsApp and Snapchat, PQChat uses the McEliece cryptosystem to provide seriously secure messaging. It uses NTS (Never-The-Same) encryption to send every single message. Meanwhile users have a greater level of control over what happens to their own messages after they are sent. You can remotely delete or protect sent messages for instance.

Other security options include setting up video- or audio passwords so that no-one but you can access your messaging account. And finally PQChat says it neither collects nor stores any message contents or personal information on its users. So even if the company itself is hacked your data is safe.

There may be other secure messaging services, and we'd love to hear from you if you know of one. Unfortunately for now PQChat is available only for iPhone and iPad, although the company tells us it is coming to Android soon. See also: How to stay private online: encrypt files, emails and browse the web anonymously.

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