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| Types of Encryption offered by Tait There are two levels of Encryption depending on your customers requirements; Voice Inversion Encryption which protects against casual listeners and Rolling/Hopping Code Scrambling which protects against more determined listeners. Voice Inversion Encryption This inverts the audio spectrum (swaps low frequencies for high) around a specific frequency, making it unintelligible. However, it is relatively easy for someone technical to experiment to find the inversion frequency, and thereafter be able to decode the audio. The bandwidth available limits this approach to only 16 different codes (which are sufficiently different to be indecipherable if you have the wrong code). This is the lowest level of security available, and the lowest cost. Rolling / Hopping Code Scrambling This inverts the audio around a frequency which keeps changing. This requires synchronisation of the inversion frequency between sender and receivers. The security of this system depends on the combination of how often the inversion frequency changes and how random the change is. The use of random codes to specify the inversion frequency allows a high level of control over the security. This allows the techniques of key generation used in digital data security to be applied, yielding immensely large number of codes, and the added security from these changing frequently as well. |
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Tait