Information Technology
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We are increasingly mobile. Data are stored on laptops, cellphones and portable USB drives. Do you ever think about what will happen if your device are lost or stolen?
As accountants, we owe a duty of care for our clients’ data. Can you imagine if your entire company financials were lost and fall into the wrong hands because your accountant lost his or her laptop? That would be very bad.
Lesson 1 – encrypt all sensitive data. Here’s how encryption works, in simple English.
Public Key Encryption
This is the encryption structure commonly being used by banks and large companies. It involve using ‘keys’, which are random combination of numbers and letters, usually at least 128 bits (16 characters) long. It is used to scramble messages so they cannot be decoded even if intercepted during transfer. The public key system is based on a set of 2 keys: the public key and private key.
The special public key can scramble a message but cannot decode them. The private key can decode the message. As the name implies, you keep the private key… um, private. Your computer browsers, for example, creates the key pair and gives the public key to the bank’s website, which in turns uses the key to encrypt your banking information. Your computer then use the private key to decode the message and display it to you.
Man-in-Middle and SSL certificates
This system has only 1 problem. What if there is a rogue employee at your Internet Service Provider (ISP, such as Telus or Shaw) who can intercept your initial public key, and replace it with his own when transmitting to the bank? The bank will unknowingly used his public key to send information to you, which he can read and re-encrypt it with your actual key before sending back to the unsuspecting you. All your information will be exposed. This is the typical ‘man-in-middle’ attack.
This is where the SSL certificate comes in. A SSL certificate is a digital certificate issued by a Certificate Authority (CA) that contains the public key and also information about the identity of you and the CA. Your browser can check with the CA to verify that the certificate is indeed from you and not altered. Your bank’s website can do the same. Therefore, man-in-middle attach cannot happen.
More Information
That’s it – encryption in a nutshell. There are obviously more details than this, but you can research it on your own if you have more time.
How Encryption Works by Howstuffworks.com
