When You Delete, Is It Really Deleted?

Computers are being more close to us day by day. Everything is being computerized. Though most of us know the ins and outs of using them, there is a lot more that we have no clue about.

Deleting a file from a storage device (Hard disk, Floppy Disk etc ;) isn’t needed to be taught to us. Everyone knows how to do it, but do you really know what happens when you do it?

In a normal computer, when you click the delete button, the file is moved to the recycle bin. So later if you need the file back, you can restore it from the bin. Suppose you need to delete it completely from your storage, all you would do is press the shift button with the delete key, and assume as, it has been deleted permanently. Though you assume it has been deleted permanently, that is not true.

Then what does really happen? As you know, computers work with bits (1s and 0s). So when you delete something, what happens is the bits are marked as empty (that new data can be put in there), but it really does not throw away the file from your storage. When a new file is overwritten on the same bits later, then the file is truly deleted, but we the normal users, think that the work is already done before it actually happens. If you have got confidential files, and you delete it just because you think someone would view it, there is still a chance that it can happen even after you delete it. Recovery tools are for that purpose. There are also erasure utilities which simply overwrites the data on top of the deleted data to avoid recovery.

What people are less known is, new technologies can recover data even after it has been overwritten. Overwriting means writing on top of something. So there remains something underneath the overwritten data. So then there should be some way to dig up the hidden data underneath. Though it is possible in some cases, it is not practical for a normal user who does not want to spend millions of rupees just to find some data.

All these information is valid only until the storage device remains magnetic.

Things That You Should Know

One hundred years ago everyone could have personal privacy, but today, it is really doubtful. In a networked world, interacting with the internet, without being watched by someone is merely impossible. Security experts, mostly known as cryptographers have done their best in order to protect our privacy throughout the cyber space. Most of the work on privacy is done by the effective use of mathematics, and most of the time, the privacy is also broken from the aforementioned mathematics. So there begins a cyber war between the cryptographers and the criminals (Let’s say so).These criminals are not like the real world criminals who commit crimes physically: at least they should be near the victim, but when it comes to the cyber world, the criminal can be thousand miles away from the victim, and still can be successful in attacking his target.

Even though I called them criminals in general, people know them as hackers. An expert hacker can break into a system and steal your private data in no time, and an expert cryptographer could use his empowered algorithms to protect your data from any hacker. Still the war exists. People are informed when the hackers win because that is what makes interesting news. The real story is cryptographers win most of the time.

I would like to explain about an attack mostly used by the hackers. It is called the “brute-force attack”. This is an interesting attack. Think that you have chosen a password for some account. A hacker badly needs to know the password. So what would be his options?  Trying out every possible password that can be typed through the keyboard is an option, but that is really boring. Obviously it is boring and an impossible task to a human, but not to a computer. So someone could write a computer program to do this, and eventually he can be successful. The time spent to the task will be depended upon many reasons. With the current security in the cyber world, a brute force attack is not that easy, a solution for the attack would be, blacklisting the ip-addresses of the users which exceed a limited number of attempts, but a network protected with weaker security can be a victim of this attack.

Assuring hundred percent security to a network is not an easy task. They say “a small hole can sink a great ship”. Same as that, a small error in the security can be the reason for a big crime in cyber space. In the present world “e-commerce” is not a new thing. A lot of money transaction is done through the internet. So a real expert in hacking can be a millionaire in just a bit of seconds. Hundreds of examples can be mentioned. The cryptographers have learned through these mistakes, and that is why today exist much more secured protocols. Experts have accepted that they are secured enough because they have been used since a long time and the holes have been patched frequently. A newly introduced protocol cannot be trusted just because no one could break in at that period of time. It needs years of experiment in public use (this is what happens in a beta version of a software) and approved by accepted security experts. So applying a new protocol to a large scaled industry is highly risky, but that does not mean that they are unsuccessful all the time.

To be a successful security expert, first you should think like a hacker. You should think of every possible way to break into the system and eventually you will end up making a very secured network. Most of the present cryptographers are past hackers. So that simply says the story. When the lion’s share of our security is done by the cryptographers, we also could use some precautions to be secured. Using hard to guess passwords and using different passwords to each account can assure us higher protection. Using the same password to all the accounts has been a trend in the internet. That is really dangerous. We don’t use the same key for our car to open the door of our house. These theories can be applied to the cyber world too.

Digital security is a vast field which needs a lot of experience and knowledge. Expertise of security experts will be highly demanding in the near future for sure. Everything is being computerized. So everything has to be secured.