128-bit SMS encryption
To ensure privacy, Kryptext wraps text messages in 128-bit encryption. Before using Kryptext for the first time, the user is verified by various methods like the unique number code of the mobile phone and password protection. Users can also set up Kryptext on their desktop to send secure SMS from their PC.
Link: http://www.pingwales.co.uk/2006/01/27/Kryptext-SMS.html
Now, I didn’t know Kryptext was 128-bit… I thought it was just ‘encrypted’ … I dunno, hashed up or something. So here’s another article by Pingwales discussing it a little more.