Security

The Secure Voice software is a high security software to protect mobile  GSM communication. Depending on your needs and wishes, there are several versions of Secure Voice.

Standard version uses RSA 1024 Session keys, AES 256, Random session key and much more to ensure your privacy.

The software is matching TOP SECRET level of confidence.

High Security version uses Diffie-Hellman 4096, AES 256, Man-in-the-middle protection with STS, random hardware generator.

VIP version uses your own custom security algorithm to ensure the best protection.

Please read some notes from the security authorities before proceeding to full specs:

RSA Laboratories currently recommends key sizes of 1024 bits for corporate use and 2048 bits for extremely valuable keys like the root key pair used by a certifying authority. [link to full text]

The US Government announced that AES may be used for classified information:
"The design and strength of all key lengths of the AES algorithm (i.e., 128, 192 and 256) are sufficient to protect classified information up to the SECRET level. TOP SECRET information will require use of either the 192 or 256 key lengths."[link to full text]

Secure Voice technical specification:

Voice encryption algorithm	AES 256/AES256+ARC4/Choice of Customer Specific Algorithm
Key exchange algorithm	RSA / Diffie-Hellman / custom algorithm
Call authentication algorithm	RSA 2048 or RSA 1024 on customer choice
Voice compression	AMR-NB 4.75 Kbps
Security - voice encoding	End-to-end
Way of communication	Full-duplex
Roaming support	Yes
Man-in-The-Middle protection	STS protocol
Protection against eavesdropping equipment (hard- and software)	Yes
Voice quality	Excellent, with almost no delays

Please also check the availability of Secure Voice for your Nokia device at devices section.