selected from a PGP list. Users compare the strings by reading them out to each other. Because SAS has the potential to generate more than 65,000 different values, it’s almost impossible for MitM attackers to succeed because they would need to guess the correct key value in order to intercept the call.
As if this wasn’t germany telegram secure enough, key commitment adds extra reassurance by using some of the key in ensuing key agreements between the same callers. This makes it even harder for MitM attackers because an attack would require knowledge of the first call between the parties using voice termination providers such as IDT.
Obviously, this requires a little work by the user, but simply by reading a word pair, they have the peace of mind that they are using a secure line and that their communication is encrypted.
Implementing ZRTP can be managed at various levels of the communication structure. It’s possible to implement it on some PBX systems, for example. It’s also available for many different makes of IP phone. There are also both open source and commercial implementations available for installation onto a communications gateway so that ZRTP calls can be made using SIP-based PBX and any ZRTP capable phone.
ZRTP can be used on mobile networks too; implementations are available for Android, Blackberry, iOS and other mobile phone operating systems. Whatever your phone system, therefore, ZRTP can be used to protect your calls.