Cryptophone, which is part of Berlin company GSMK, has developed a cell phone which encrypts conversations so no one can eavesdrop on them. It sells for 1,900 Euros ($2,270 US) and it will be sold in the US by the end of 2003.
AES256 and Twofish algorithms are used to encrypt and these are considered to be some of the strongest ones out there. The source code used for the encryption is completely available so auditors can look for security problems.
This is not the first cell phone to use encryption technology but it is one of the most secure. Law enforcement authorities fear the criminals will use phones like these. Cryptophone tells users on its web site that such monitoring could occur. Source