Voice encryption over gsm by use raspberry pi 3 b+

GSM is the most wide spread mobile communications system in the world. However the security of the GSM voice traffic is not guaranteed especially over the core network. It is highly desirable to have end-to-end secure communications over the GSM voice channel. In order to achieve end-to-end security, speech must be encrypted before it enters the GSM network . ‎‏Project requirements: ‎‏No JB, Do not install APP, No Internet Connection ‎‏Analog Voice Encryption ‎‏Encrypting voice of mobile calls (GSM, CDMA, LTE, APP ... calls) directly. Encrypt voice contents before sending into cell phone. Prevent intercept at phone, base station and Telecom server site. Analog encryption guard against crack and hack. Secure your voice contents extremely. ‎‏No APP Installation ‎‏No Server involvement ‎‏project doesn’t need internet connection. project communicate through voice channel. Won’t save or transfer log/key by 3rd party. Less exposure and higher security. ‎‏Provide unlimited encrypted phone call minutes. No licenese limitation. Secure phone call forever. ‎‏The phone is used to send encrypted voice between the parties. ‎‏The piece contains two parts ‎‏Part of the sender ‎‏Part of the receiver ‎‏Where the sender - sends the encrypted voice by phone to the other part ‎‏The receiver part decrypts the voice and hears it normally End to end encrypt