The encryption algorithm used by the Xceed Zip Compression Library, Xceed Zip for .NET, Xceed Zip for .NET Compact Framework, Xceed Backup and Absolute Packager is the same one used by the PKZip 2.04g program.
This type of encryption can resist attacks by amateurs if the password is well chosen and long enough (at least 16 characters) but it will probably not resist attacks by determined users or experts. Therefore, we suggest that you always use long passwords, and when possible, do not rely solely on this encryption system to protect sensitive data.
Xceed Zip Compression library 6.0 also supports AES encryption. Xceed Zip for .NET will support AES encryption in the May 2006 release.
Imported from legacy forums. Posted by Xceed admin (had 2022 views)