Please allow 1-2 weeks delivery time
EP-880 Scramble Encrypted Anti-Tapping Phone
EP-880 Scramble Encrypted Phone is designed for voice communication protection by our unique Frequency Band Scrambling (FBSS) technology. Secure voice communication over public telephone networks can be achieved by integrating this technology with normal telephone functions.
The EP-880 is a analogue scramble encrypted phone. Frequency Band Switching and Scrambling ensures the voice transmission remains secure.
EP-880 comes with 743 billion cryptographic codes, which are randomly set. The EP-880 is very user friendly, encryption can be achieved if one of both calling partners press the encryption button. (Caller and Receiver need 1 model EP-880 phone each)
The EP-880 needs only to be connected with the PSTN line. During a normal conversation, by pushing the encryption button both phones will start to encrypt. So you just need to push one button, and both phones will encrypt. Therefore we sell, the phone always with at least two pieces.
Features 1) EP-880 is equipped with all the features and functions of a normal telephone. 2) The two parties can communicate in a secured environment when they are both using the EP-880. 3) EP-880 allows switching between secured operation mode and normal operation mode by press one button. 4) High security communication is supported by dynamic frequency change and scrambling technique of FBVS which makes decoding almost impossible. 5) EP-880 interlocks the link between 2 communication parties, blocking out any 3rd party even if it uses an EP-880. 6) EP-880 is equipped with an automatic identification function of Normal or Scrambling mode communication. If the 2 parties are using EP-880, it will be able to detect so and will automatically engage into scrambling mode communication and a green light will flash. If one of the 2 parties is not using EP-880, it will detect so and will automatically engage in Normal mode communication and no flash light will appear.
EP-880 SPECIFICATIONS 1 ringer output 1.1 Ringer sound level(at 20Hz, 75Vrms) ≧ 70dBA
2 DC Characteristics 2.1 on Hook (resistance 80VDC) > 5M 2.2 Off Hook @20mA < 9V
3 Frequency Responses 3.1 Transmit U.S.A 3.2 Receive U.S.A
4 Objective Loudness Rating 4.1 TOLR 4.1.1 @0K ft -53 ～ -40dB 4.1.2 @15K ft -49 ～ -36dB 4.1.3 TX Distortion ≦ 5% 4.2 ROLR 4.2.1 @0K ft 41 ～ 51dB 4.2.2 @15K ft 45 ～ 55dB 4.2.3 RX Distortion ≦ 5% 4.3 SOLR 4.3.1 @0K ft > 4dB 4.3.2 @15K ft > 4dB 4.3.3 SOLR Distortion < 8%
5 Return Loss 5.1 @0K ft 5.2 200 Hz ~ 3500 Hz > 10dB
6 Echo Return 6.1 @0K ft 6.2 500 Hz ~ 2500 Hz > 15dB
7 DTMF Dialing Test 7.1 @20mA Low Group -10 ～ 0 dBm 7.2 @20mA High Group -8 ～ 0 dBm 7.3 Twist Level 0 ～ 4dB 7.4 @80mA Low Group -12 ～ 0 dBm 7.5 @80mA High Group -10 ～ 0 dBm 7.6 Twist Level 0 ～ 4dB 7.7 Frequency Deviation < 1.5% 8 Flash Time 600ms±30ms
9 CID 9.1 Type FSK Signal Level Detection(S/N 25dB) -12 ～ -44dBm 9.2 Type DTMF Signal Level Detection(S/N 15dB) -32 ～ -4dBm 10 Operation Current ≦ 250mA 11 Standby Current ≦ 250mA
Frequency Band Switching and Scrambling
Frequency Band Switching and Scrambling is different from code encryption technology. It is mainly used in securing voice transmission to ensure high confidentiality, making it extremely difficult to decode.
A brief description: by changing certain frequency F(x) to F(y) and producing different carrier frequencies within a frequency range, we choose various modulation frequencies and demodulation frequencies. Based on this, F(y1, y2… yn) carrier frequencies will be changed within different time domains T (t1, t2……tn) to achieve “frequency-hopping order mechanism” of both frequency domain and time domain, thereby actualising scrambling and descrambling functions on analogue communications to ensure information security.
The technology integrates normal telephony functions, scrambling module and descrambling module. First the caller’s terminal divides voice frequency band into different frequency bands which are to be scrambled, mixed with modulating frequencies and then output. Receiver’s terminal reservation mechanism will do reverse processing to complete descrambling. Division of band in this technology varies randomly. The scrambling key also varies according to random permutation. Scrambling technology does not have a rigid receive-call synchronization mechanism scrambling and descrambling, could only be correctly done by both calling parties.
Mode of scrambling: during conversation, process scrambling and descrambling among different carrier frequencies. The variation of carrier frequencies is accomplished by software, therefore difficult to be deciphered.
The IC chip a brief description
The chip IC is a frequency domain scrambler for the use inside the analogue phone systems. It contains separate Tx and Rx paths for full duplex operation and operates under Processor control via simple serial interface.
In the Tx path, scrambling is achieved by splitting the audio band into two parts, or sub-bands, and frequency inverting each one. The frequency at which the signal is split, the “Split-point” can be either fixed or rolling between four possible settings resulting in a transmitted audio signal which is unintelligible to eavesdroppers. Descrambling is achieved by a receive device set to the same split point as the remote transmitter. Thus if the Tx and Rx devices are synchronously cycled through the same sequence of split points, a clear recovered signal will emerge at the output of the receiver.