The IDEATM block cipher is patented by Ascom-Tech AG. The Swiss patent number is PCT/CH91/00117, the European patent number is EP 0 482 154 B1, and the U.S. patent number is US005214703. IDEATM is a trademark of Ascom-Tech AG. There is no license fee required for noncommercial use. Commercial users may obtain licensing details from MediaCrypt AG at IDEA@mediacrypt.com.
You can use IDEA encryption for noncommercial communications without a license; commercial use is prohibited without a license. If you don't want to obtain a license from MediaCrypt, use AES, Blowfish, DES, or key file encryption instead.