Secure Communications
When you send information over the internet, it travels through a multitude of computers, any one of which could be set up to read what you're transmitting or reading. This is obviously a problem if you intend to send personal or financial details to a remote website. However, there are a number of ways in which you can protect your details online.
Secure Socket Layer (SSL)
The Secure Socket Layer protocol is designed to let your computer communicate with remote computers in a way that prevents anyone spying on the information being transferred between the two. It uses complex cryptography to ensure that the two communicating computers are who they say they are and it encrypts the data flowing between them. Modern browser programs are capable of communicating using the SSL, although they are not the only programs to use the technology.
It works as follows;
- Your computer tries to access information which is stored on a secure internet server.
- The remote server tells your computer that the information is secure.
- Your computer sends the server a list of the security measures it knows. (And it will know several.)
- The server selects one of those measures that it also knows and tells your computer which one it is going to use.
- The two computers swap 'certificates', complex cyphers which describes how each side wants the other to encrypt the data being sent. While any computer listening in can use the cypher to encrypt data, only the computer that created the cypher can decrypt the data. This is done using some extremely complex mathematics.
- Your computer and the server will then use this message system to pass your credit card numbers, address, banking details and so on securely.
Most web pages are unencrypted and use HTTP (Hyper Text Transfer Protocol), including the page you are currently reading (if you are reading this page online). Look at the browser address bar and notice the start of the web page address is http://. When your browser is directed to a SSL secured webpage, the http:// will change to https://. The additional s is a sure sign that your computer is transmitting securely. There are a number of other indicators you can look out for.
Most browsers will display a message box telling you you are about to switch to an SSL encrypted page. This is the Internet Explorer box.
The Firefox browser turns the address bar yellow, and adds a padlock to the end of the bar.
Internet Explorer leaves the address bar the same colour but adds a padlock icon to the bottom right of the page.
The padlock icon indicates that the page is using SSL, but only if the padlock is part of the browser. Fraudsters often leave images of a padlock in the actual web page content as an attempt to fool people reading the page. Additionally, if you click on the padlock symbol in some browsers, you can see a certificate of authentication from Verisign.
E-mail Security
To put it bluntly, there is no such thing as e-mail security. E-mails are sent unencrypted, they can be read by every computer that they pass through on their journey across the internet, and the company that provides your e-mail server probably keeps a copy of all your recent e-mails. (This is not a malicious action, generally. The company might accidentally copy e-mails when backing up their servers, or the e-mail could have been deleted in name only, but still be readable with file recovery software.)
While programs exist which can encrypt e-mails, they are not widely used or well understood by the common user and as such are rarely used. As a result, you should never use e-mail to transmit valuable or personal data.
Virtual Private Networks
Virtual private networks is an name given to a number of encrypted communication techniques designed to let a person link their computer to a private network (a home or business network) over the internet, without letting any computer that is not part of the intended network read the data being sent. The method of connecting a computer to a VPN is very straightforward.
- The user gains access to their computer using a password, smart-card reader, fingerprint reader (no, really!).
- The computer tries to gain access to the remote network using a system very similar to Secure Socket Layer authenticcation (above). In fact, some VPNs use SSL for the authentication.
- Once connected, the user can communicate with the remote network as if they were in the same room, with all the usual privileges and access they would normally have.
Virtual private networks are used by business people on the move, people who work from home, computer technicians to remotely repair computer networks, and more recently, by people who want to stream music and movies from their home computers onto mobile devices as they travel. Sending an e-mail across a VPN is far more secure than a regular e-mail, but the downside is that only someone else on the VP network can receive it.
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