Is it possible to recover a lost password from a RAR or ZIP?

Nowadays it is very common to compress one or more files so that they can be sent, shared or simply saved. For this, there are a lot of tools that allow us to do it and create files with the most popular formats such as .ZIP or .RAR. In certain cases, it is convenient to protect the compressed file that we send or send us with a password and later have access to it only if we know the password that protects it and thus prevent anyone from having access even if it falls into the hands of strangers.

However, as happens whenever we use a password to access some content, account or in this case file, we may have forgotten or lost and we can not access the file in question. When it comes to a service or account, the normal thing is that we can perform a process for recovery or change, but in case we forget the password that protects a compressed file, the thing changes, and quite a lot.

This time we are complicated the thing, since it is not easy to be able to recover the password of a ZIP or RAR file. It is then when the question arises whether it is possible or not to recover this type of passwords in some way. The truth is that the exact answer would depend, since there are several aspects that can determine if we will finally be able to recover or not this type of passwords.

There are some tools that have been designed with this goal, but even so, it is possible that in some cases they will not be able to recover the lost password. Although some of the most powerful are paid, there is a pretty good one that can be used in your free trial to recover the lost or forgotten password of a compressed file. We refer to ARCHPR, although it is not free if it offers a trial version before we decide to buy it.

Like other tools of this type, ARCHPR is based on performing different types of attacks to guess the access password and get open the compressed file. One of them is brute force, a method to try to find out all possible password combinations until you find the correct one. For this method to work, we will have to limit the characteristics of the password as much as possible, ie if it was composed only by digits, length, if it contained special characters, etc.

If we also remember how it started or how it ended, we can get ARCHPR to give us access to the protected file, if not, it may take so long that we finally give up and we can not recover it.

Another type of attack by which ARCHPR tries to recover the lost password is the famous attack by dictionary, which as its name indicates, uses a dictionary of words to carry out its mission, that is to say, it uses a dictionary with frequent words and the Program will automatically check one by one to decrypt them.

The mask attack allows you to create a mask of flexibility to specify the exact position of a certain character, whether they are case sensitive or not. Therefore, the ability to recover a forgotten password will depend on the type of attack we execute, according to the tool we use for it, and everything we remember from it so that the attacks are as effective as possible. In any other way, we are going to encounter eternal processes that can not be solved in an acceptable time frame.