1)   1Crypt 1.03
A quick and professional way to add strong encryption to your application. 1Crypt is a function library (DLL) which allows you to easily encrypt files, strings, and buffers using 256-bit Advanced Encryption Standard (Rijndael) encryption.

 2)   .NET ZIP Component for CS VB ASP.NET 3.0
NetXtremeZip is an advanced ZIP compression library for .NET Framework. With this component, your application can compress and decompress files and folders easily.

 3)   Zip Component for .NET C#, VB.NET, ASP.NET 1.6
NetXtremeZipLite is an advanced ZIP compression library for .NET Framework. With this component, your application can compress and decompress files and folders easily.

 4)   .NET ZIP Component for CS VB.NET ASP.NET 2.0.313.626
A high-speed, reliable Zip library with affordable price which lets you add zip/unzip functionality to your .NET applications with only few lines of code.