SIM Cards

SIM Cards and SIM Security

Many people who have owned a mobile phone have heard the term “SIM card”. SIM cards are a necessity to the use of most cell phones and some other electronic devices. But what are they? What purpose do they serve? Why are they so important to use?

“SIM” stands for “subscriber identity module” or “subscriber identification module”. It can be found in various computers and most mobile phones. Its purpose is noted in the acronym of its name: It authenticates the identity of and authenticates the data for the user who possesses it. SIM cards are also used to activate mobile phones and store the phone number of the user. They can also store data, such as messages and contacts that are on the device.

Because SIM cards have been around for about as long as mobile devices have, there are a variety of different sizes to accommodate advances in technology and the different kinds of devices we now have and use in our everyday lives. There are five different sizes: Full size SIM, Mini-SIM, Micro-SIM, Nano-SIM, and Embedded-SIM. Full size SIM cards were the first to appear, first showing up back in 1991. The entire thing was about the size of a credit card. It consisted of the metal contact area and a large amount of plastic surrounding it to make up the rest of the card, which helped to prevent things like short circuiting. Over the years, the contact area has remained largely the same size and design, with the plastic portion getting smaller and smaller with each type of SIM card. This allows for the user to cut out the particular size needed for their device. The next size to appear was the Mini-SIM. It is quite a bit smaller than the full sized SIM. Considering that the full size is no longer produced or used anymore, the Mini is also known as the “standard SIM”. The invention of this smaller card began the previously mentioned trend of SIM cards being sold in forms with cutouts so that customers had options for which size they could use.

Next came the Micro-SIM, which was first introduced in 2010. As the Mini is smaller than the Full Size, the Micro is smaller than the Mini. As before, though, it wasn’t the contact area that was smaller, it was the surrounding plastic. This continued when the Nano-SIM was introduced in 2012, which had very little plastic surrounding it at all. Still, there needed to be some plastic in order to protect the contact area from damage. The last kind of SIM card is the Embedded-SIM. It is exactly as it sounds, built right into the circuit boards of the device itself as part of the manufacturing of the product. This sort of SIM card could be helpful in that users don’t have to buy a separate card from their device, but it proves more difficult when the SIM card can’t simply be removed and transferred to another device as other SIM cards can be. If someone were to purchase a new phone, it would be relatively easy to simply transfer one of the more portable SIM cards to the new phone.

With something as important as personal data and phone numbers and phone contacts at stake, it is important to consider whether or not SIM cards are secure. The answer is that, for the most part, they are. As technology grows and changes every year, so do the protections available to SIM cards. But, technology can sometimes fail and there have been some security issues in both the past and present. In 2013, a few studies found that SIM cards that still supported older encryption systems were more at risk to hacking than those that worked on newer systems. This, of course, was taken under careful consideration as it could lead to data breaches. In 2015, it was revealed that the NSA had potentially stolen encryption keys, which would allow them to monitor data and communications without the knowledge or permission of a cellular service. SIM cards are required for use of most mobile phones and also contain very important personal information, so a data breach of that kind is especially concerning. Even now, in present times, there are ways for hackers and scammers to get into SIM cards and steal data, but there are ways for individuals to protect themselves should this happen. Keep track of everything your phone number is used for and make note if something is out of place, as it could indicate an issue with the SIM card that your phone number is attached to. If something is wrong, contact your cellular provider and ask for help.

SIM cards are very important in the lives of anyone who uses personal and handheld technology. Without them, most phones would be rendered useless and consumers would not be able to transfer their contacts and phone number to a new device. Plus, SIM cards can be used to authenticate identity since phone numbers are often associated with them and typically there is only one person per phone number. SIM cards can certainly seem complicated at first, especially because it can often be confusing as to what is stored on the device itself and what is on the SIM card, though some of that can even be determined by the individual and how much they want stored on the card. But, really, SIM cards are fairly simple when it comes to the amount of knowledge you need in order to use it every day. There are various shapes and sizes, but they all do the same thing: store important data and activate phones. And, yes, there are some occasional security issues as outlined previously, but the reality is that security can be an issue with just about any technology and there are ways to keep yourself safe. SIM cards have been part of technology since the early 1990s and have changed as personal devices do. Because of this they will likely be part of personal technology for a very long time.