ReliaSpeak™ BLUEBOX20
Digital Encryption Headset

Bluetooth headset, paired with iPhone or Android phone,
supporting encrypted calls over GSM, UMTS, VoLTE,
Skype, WhatsApp, FaceTime...


Currently, commercial encrypted headset products are generally applying scrambling technology. However, no matter how complicated the scrambling solution is, “the residue of speech intelligibility” will be existed. That is, there will be a speech characteristic vulnerability that can restore the scrambled voices to the original voices without cryptographic algorithm cracking. All this has been proved that commercial encrypted headset products using scrambling technology will not be secure enough for encrypted calls.

By adopting AMSI digital modulation technology, BLUEBOX20 can transmit high reliability data through voice compressed and coded channels (e.g. cellular calls, VoIP, etc.), and realize end-to-end encrypted communication by using digital voice encryption technology.

The process of BLUEBOX20 is: compress and code the user’s speech first, then encrypt the coded data with high-strength cryptographic algorithm, modulate the encrypted digital stream to audio signal that is similar to the sound of fax Modem and send to the phone. Therefore, there will be no any speech intelligibility residue in the voice channels during the transmission of audio signal. Eavesdroppers can only decrypt the encrypted voices by cryptographic algorithm cracking. The security level of BLUEBOX20 is totally determined by the adopted strength of cryptographic algorithm.

The cryptographic algorithm adopted by BLUEBOX20 is fully compliant with the highest commercial security standards :

■ key agreement algorithm: ECDH, dynamic key negotiation

■ speech cryptographic algorithm: 3DES, CTR mode

BLUEBOX20 adopts voice source encryption solution. Users’ voice has already been encrypted before sending to the phone devices, that can resist the risk of eavesdropping to the maximum extent, not only could prevent line eavesdropping from carriers, network, SS7, cellular interceptor, but also could prevent eavesdropping from mobile spywares, backdoors, etc.



BLUEBOX20 supports iPhone7 or higher,  and most of the Android smartphone with Qualcomm 845 , Kirin 970 or higher chipset.。

Yes, both sides must use BLUEBOX20 for encrypted calls. Otherwise, one side encrypts the voice, another side can’t decrypt it.

Yes, but you need to select carriers who support GSM (using EFR or AMR speech coding), UMTS or VoLTE. BLUEBOX20 can not be used under CDMA or CDMA2000 network. In addition, for roaming and international long-distance calls, the effect of encrypted calls can not be guaranteed due to the different technical standards adopted by different carriers, as well as the possible problem caused by speech transcoding.

Frankly speaking, there are too many VoIP applications to be tested one by one. Generally, VoIP applications with good voice quality can support encrypted calls. Here are some common VoIP applications that have been proven to work, such as Facetime, WhatsApp, Line, Skype … For other VoIP applications, you need to test and discover them yourself.

Yes, BLUEBOX20 could be used to make encrypted calls as long as your phone is connected to the internet and VoIP calls are in normal status. The effect of encrypted VoIP calls is related to network bandwidth, latency, and package loss rate. It is recommended to choose 4G network or 5G Wi-Fi as prior options.

BLUEBOX20 connects to the mobile phone via Bluetooth. There will be signal interference if both Bluetooth and Wi-Fi use the same frequency band of 2.4GHz, resulting in loss or distortion of the modulated waveform of encrypted calls transmitted by Bluetooth, thus will cause worse sound quality. In addition, It is also found that different brands and models of mobile phones have different degrees of interference (mainly due to the differences in antenna design). In order to avoid  signal interference completely, It is recommended to choose 4G/5G network or 5.8G Wi-Fi as prior options.


pplicable mobile phone modelsiPhone7/8/X/11, Huawei Mate20/P30, Samsung S9/S10…
Connecting methodBluetooth
Supported cellular voice communicationsGSM、UMTS、VoLTE
Signal requirements of encrypted callGSM: >-90dB; UMTS: > -90dB; LTE (VoLTE): > -100dB
Supported VoIP communicationsWhatsApp, Skype, Line, Facetime, Signal…
Speech coding rate of encrypted call1.2kbps
Switching time of encrypted/normal call<10s
playCryptographic algorithmkey agreement: ECDH;
data cryptographic algorithm: 3DES, CTR mode
Battery lifecall duration: 2.5 hrs; standby time: 15 hrs
Indicator lightPower-on indication, Bluetooth status indication,
battery/charging indication,
normal/encrypted call indication
Dimensions86mm * 52mm * 10mm; weight: 38g
External interface3.5mm headset jack; Micro USB interface
Charging5V 1A DC power adapter
PackageBLUEBOX20 X 1; 3.5mm earphone X 1; USB cable X1; manual/warranty card

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