Wi-Fi, the technology which allows you to surf the net wirelessly without the cumbersome ethernet wire connection (or the modem connection), is a very convenient feature which many used everyday without much thought. However, as the signals are transmitted through-the-air, it is possible for anyone in the vicinity to eavesdrop into the connection. To prevent this, you need to use encryption.
There are currently a few wireless encryption standards used: 64-bit WEP, 128-bit WEP, WPA and WPA-2. WPA and WPA-2 are the newer standards and might not be available on the device if it was bought 2 or more years ago.
I used to think that 128-bit WEP is very secure; afterall there are 2^128 combinations, which is roughly equals to 3.4 x 10^38 combinations (that’s 34 followed by 37 zeros behind). To put this number into perspective, if we can test a combination in one nanosecond (one second divided into a billion intervals), it will take 1.08 x 10^22 years to run through all the combinations.
Recently, I found that I was badly mistaken. A 128-bit WEP can be cracked in a matter of a few hours; and the 64-bit (40-bit) version can be cracked in a matter of a few minutes. You can read about this in Tom’s Networking HERE.
The solution is to move to the more advance WPA or WPA-2 encryption scheme.
Note: Cracking WEP means that the hacker will have a “physical” connection to your network; it does not mean he/she will have access to your files. That access is usually controlled by the operating system’s file sharing mechanisms.