How Strong Is 7-Zip Encryption?

By G.S. Jackson

The 7zip archive format also applies strong AES-256 encryption.
i Stockbyte/Stockbyte/Getty Images

File compression allows for the transfer of files more readily and more quickly over the Internet. File compression and encryption by the 7Zip application means that more information can be sent in a more secure manner. 7Zip uses AES 256-bit encryption, which presents a powerful method of data security. To understand how strong this is, you must understand the AES standard and encryption key strength.

AES Encryption

The Advanced Encryption Standard, developed by the National Institute for Standards in Technology, outlines an encryption method using a complex encryption procedure and employing nearly unbreakable encryption keys. The AES encryption standard was developed for the increasing use of digital communications within the federal government and financial institutions, which necessitated a strong encryption system to protect state secrets, medical records and financial information.

7Zip Archiving and Encryption

The 7Zip application functions as an archiving and encryption utility. 7Zip archives data by compressing it into a small file. You can take a number of files and run it through 7Zip, which will then compress the files into a smaller size and store them in a single file for transport. You can also encrypt the file so that others cannot open it without the proper encryption key.

256-Bit AES Encryption

The AES specification outlines encryption levels for 128-, 192- and 256-bit encryption, each of which would take roughly billions of years to break through brute-force attacks. This encryption standard is strong and is used for federal communications. Since the specification is open to others to implement, the AES encryption provides strong protection to anyone who uses -- not just the government -- it as a security measure.

Strength of 7Zip AES Encryption

7Zip uses AES 256-bit encryption, the strongest version of AES. This means that a file encrypted is considered unbreakable without the encryption key, and guessing the key through brute force attacks will be equally impossible unless a particular scheme is discovered to crack AES keys. However, 256-bit encryption is computationally complex and requires time and energy to implement, so encrypting and decrypting large files or messages might take some time, especially over Internet connections.