Simple, fast and secure transmission of confidential content.

Sending confidential content by e-mail is a fairly common practice. Unfortunately, not always people exchanging information with each other are able to take advantage of such facilities as encrypted e-mail communication, encryption keys or certificates. If sending confidential data is incidental and is not systematically resolved by the IT department, users often resort to the simplest measures in the form of office suite files protected with a password or compressed with a password-protected program such as winzip or winrar. Such solutions, although they seem safe, are characterized by a high level of risk. For the sake of compatibility, the most popular document formats are saved using low-security algorithms. There is a whole range of tools available to help crack passwords for files in the .doc, .docx, .xls, .xlsx or .zip formats.

So how to deal with a situation when the data we want to send must be quickly and securely delivered to the recipient? A free program, licensed under the GNU LGPL license, comes to our aid here 7zip. It allows you to compress files using the AES-256 algorithm with a 256-bit key length. Moreover, in order to make it difficult to crack the password with dictionary or brute force methods, the key is saved in an iteration of several hundred repetitions. This means that checking each entry from a dictionary or generator requires several hundred times more time than in the case of other formats. While when saving or reading a file, this difference is imperceptible to the user, for a potential intruder the effect is as if instead of a modern processor he was using a museum exhibit to break the password.

So when using compressed 7zip The AES-256 algorithm and the appropriate long (several characters), non-dictionary password can easily protect your confidential files. Of course, it should be remembered that in the case of sending them by e-mail, the password should be provided to the recipient by another channel, e.g. by means of a text message.

In order to use the functions described, which increase security, you should archive files according to the following instructions:

1. Right-click on the file or directory and select: "7-zip -> Add to archive ..." from the context menu
2. In the opened window, select Archive format: 7z and Encryption method: AES-256 and enter a long, non-dictionary password in the "Enter password" field.
3. Click "OK"