If your name is George W. Bush or Vladimir Putin I do have the perfect phone for you:

The Siemens Gigaset SL965

With the Gigaset SL965 crypto phone , you can be absolutely sure that you are making secure calls , thanks to the encryption key generation that takes place right in the handset. It's the world’s first cordless DECT telephone with point-to-point call encryption.

Up to now, many people have depended on secure telephone lines for their communication, but that usually meant accepting some limitations in quality and convenience.

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For example, before the SL965, call encryption was only possible via room-bound, corded telephones with a voice quality that left much to be desired.

The Siemens Gigaset SL965 retains the audio advantages of a traditional Gigaset cordless phone for crystal-clear calling combined with the piece of mind that can only come from a crypto phone .

In addition to improved voice quality, the Siemens Gigaset SL965 also features an extended range that was never possible with corded crypto phones. Since all the authentication and encryption happens in the handset, the user is provided with a ‘tunnel of privacy’ that offers the distinct advantage of mobility. Many eavesdroppers simply use ‘bugs’ that operate independently of the telephone by recording local sound. Using the SL965 security phone allows you to avoid such bugs and make important calls away from potentially compromised areas.

Thanks to its digital signal processor, the Siemens Gigaset SL965 features the latest encryption standards including the world’s first 3072-bit Public Key generation. For maximum security, the entire key generation, key exchange, and encryption takes place in the handset itself. A new key is generated for each call, and destroyed as soon as the call is finished. The strongest and most secure algorithms commercially available guarantee your calls are only heard by the person you’re calling.

When making a normal voice call, simply press the ‘#’ key to go secure. The display will take you through the key exchange necessary to establish a secure phone line. Once the secure key is established, the callers authenticate the call by entering the PIN code generated by the handset. Once both parties have entered the PIN, the phone clearly displays a key icon indicating that the line is secured.

As you are one of the "leader of the world" it should be no problem for you that one phone costs around 1.800 Euro. A pair is available for around 3.000 Euro.

More features can be found here:
Siemens Gigaset SL965