This is the software publisher's description.

Designed to compress a group of files/folders to a single encrypted file.

Compression utilities such as Zip, Arj, RAR and many others are really helpful in saving hard disk space. However, in many cases the data we compress is private. The question of privacy is even more important when we wish to send compressed data over insecure Internet connections. There are powerful encryption algorithms and technologies that can help people keep their private data in a secure form. But it is important:

Using BCArchive is very simple yet very secure. Let's say you want to back up some data and store it as compressed, encrypted archive on your hard drive. All you need to do is specify a password for the archive when you create it and enter the same password to decrypt and extract the data. This simple process requires no special knowledge of encryption.

BCArchive uses powerful algorithms, such as IDEA and Blowfish to encrypt the data and the PKCS #5 standard for derivation encryption key from the password string. Beware of trusting your data to less sophisticated encryption programmes because the archives they create can often be cracked with a simple freeware utility.