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PGPfone
PGPfone was a secure voice telephony system developed by Philip Zimmermann in 1995. The PGPfone protocol had little in common with Zimmermann's popular PGP email encryption package, except for the use of the name. It used ephemeral Diffie-Hellman protocol to establish a session key, which was then used to encrypt the stream of voice packets. The two parties compared a short authentication string to detect a Man-in-the-middle attack, which is the most common method of wiretapping secure phones of this type. PGPfone could be used point-to-point (with two modems) over the public switched telephone network, or over the Internet as an early Voice over IP system. In 1996, there were no protocol standards for Voice over IP. Ten years later, Zimmermann released the successor to PGPfone, Zfone and ZRTP, a newer and secure VoIP protocol based on modern VoIP standards. Zfone builds on the ideas of PGPfone. According to the MIT The Massachusetts Institute of Technology (MIT) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PGP Word List
The PGP Word List ("Pretty Good Privacy word list", also called a biometric word list for reasons explained below) is a list of words for conveying data bytes in a clear unambiguous way via a voice channel. They are analogous in purpose to the NATO phonetic alphabet used by pilots, except a longer list of words is used, each word corresponding to one of the 256 distinct numeric byte values. History and structure The PGP Word List was designed in 1995 by Patrick Juola, a computational linguist, and Philip Zimmermann, creator of PGP. The words were carefully chosen for their phonetic distinctiveness, using genetic algorithms to select lists of words that had optimum separations in phoneme space. The candidate word lists were randomly drawn from Grady Ward's Moby Pronunciator list as raw material for the search, successively refined by the genetic algorithms. The automated search converged to an optimized solution in about 40 hours on a DEC Alpha, a particularly fast machine in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comparison Of VoIP Software
This is a comparison of voice over IP (VoIP) software used to conduct telephone-like voice conversations across Internet Protocol (IP) based networks. For residential markets, voice over IP phone service is often cheaper than traditional public switched telephone network (PSTN) service and can remove geographic restrictions to telephone numbers, e.g., have a PSTN phone number in a New York area code ring in Tokyo. For businesses, VoIP obviates separate voice and data pipelines, channelling both types of traffic through the IP network while giving the telephony user a range of advanced abilities. Softphones are client devices for making and receiving voice and video calls over the IP network with the standard functions of most ''original'' telephones and usually allow integration with VoIP phones and USB phones instead of using a computer's microphone and speakers (or headset). Most softphone clients run on the open Session Initiation Protocol (SIP) supporting various codecs. Sk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phil Zimmermann
Philip R. Zimmermann (born 1954) is an American computer scientist and cryptographer. He is the creator of Pretty Good Privacy (PGP), the most widely used email encryption software in the world. He is also known for his work in VoIP encryption protocols, notably ZRTP and Zfone. Zimmermann is co-founder and Chief Scientist of the global encrypted communications firm Silent Circle. Background He was born in Camden, New Jersey. Zimmermann received a B.S. degree in computer science from Florida Atlantic University in Boca Raton, Florida in 1978. In the 1980s, Zimmermann worked in Boulder, Colorado as a software engineer on the Nuclear Weapons Freeze Campaign as a military policy analyst. PGP In 1991, he wrote the popular Pretty Good Privacy (PGP) program, and made it available (together with its source code) through public FTP for download, the first widely available program implementing public-key cryptography. Shortly thereafter, it became available overseas via the Intern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secure Telephone
A secure telephone is a telephone that provides voice security in the form of end-to-end encryption for the telephone call, and in some cases also the mutual authentication of the call parties, protecting them against a man-in-the-middle attack. Concerns about massive growth of telephone tapping incidents led to growing demand for secure telephones. The practical availability of secure telephones is restricted by several factors; notably politics, export issues, incompatibility between different products (the devices on each side of the call have to use the same protocol), and high (though recently decreasing) price of the devices. Well-known products The best-known product on the US government market is the STU-III family. However, this system has now been replaced by the Secure Terminal Equipment (STE) and SCIP standards which defines specifications for the design of equipment to secure both data and voice. The SCIP standard was developed by the NSA and the US DOD to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nautilus (secure Telephone)
Nautilus is a program which allows two parties to securely communicate using modems or TCP/IP. It runs from a command line and is available for the Linux and Windows operating systems. The name was based upon Jules Verne's Nautilus and its ability to overcome a Clipper ship as a play on Clipper chip. The program was originally developed by Bill Dorsey, Andy Fingerhut, Paul Rubin, Bill Soley, and David Miller. Nautilus is historically significant in the realm of secure communications because it was one of the first programs which were released as open source to the general public which used strong encryption. It was created as a response to the Clipper chip in which the US government planned to use a key escrow scheme on all products which used the chip. This would allow them to monitor "secure" communications. Once this program and another similar program PGPfone PGPfone was a secure voice telephony system developed by Philip Zimmermann in 1995. The PGPfone protocol had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philip Zimmermann
Philip R. Zimmermann (born 1954) is an American computer scientist and cryptographer. He is the creator of Pretty Good Privacy (PGP), the most widely used email encryption software in the world. He is also known for his work in VoIP encryption protocols, notably ZRTP and Zfone. Zimmermann is co-founder and Chief Scientist of the global encrypted communications firm Silent Circle. Background He was born in Camden, New Jersey. Zimmermann received a B.S. degree in computer science from Florida Atlantic University in Boca Raton, Florida in 1978. In the 1980s, Zimmermann worked in Boulder, Colorado as a software engineer on the Nuclear Weapons Freeze Campaign as a military policy analyst. PGP In 1991, he wrote the popular Pretty Good Privacy (PGP) program, and made it available (together with its source code) through public FTP for download, the first widely available program implementing public-key cryptography. Shortly thereafter, it became available overseas via the Internet, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modem
A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by Modulation#Digital modulation methods, modulating one or more carrier wave signals to encode digital information, while the receiver Demodulation, demodulates the signal to recreate the original digital information. The goal is to produce a Signal (electronics), signal that can be transmitted easily and decoded reliably. Modems can be used with almost any means of transmitting analog signals, from light-emitting diodes to radio. Early modems were devices that used audible sounds suitable for transmission over traditional telephone systems and leased lines. These generally operated at 110 or 300 bits per second (bit/s), and the connection between devices was normally manual, using an attached telephone handset. By the 1970s, higher speeds of 1,200 and 2,400 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secure Communication
Secure communication is when two entities are communicating and do not want a third party to listen in. For this to be the case, the entities need to communicate in a way that is unsusceptible to eavesdropping or interception. Secure communication includes means by which people can share information with varying degrees of certainty that third parties cannot intercept what is said. Other than spoken face-to-face communication with no possible eavesdropper, it is probably safe to say that no communication is guaranteed to be secure in this sense, although practical obstacles such as legislation, resources, technical issues (interception and encryption), and the sheer volume of communication serve to limit surveillance. With many communications taking place over long distance and mediated by technology, and increasing awareness of the importance of interception issues, technology and its compromise are at the heart of this debate. For this reason, this article focuses on communicatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ZRTP
ZRTP (composed of Z and Real-time Transport Protocol) is a cryptographic key-agreement protocol to negotiate the keys for encryption between two end points in a Voice over IP (VoIP) phone telephony call based on the Real-time Transport Protocol. It uses Diffie–Hellman key exchange and the Secure Real-time Transport Protocol (SRTP) for encryption. ZRTP was developed by Phil Zimmermann, with help from Bryce Wilcox-O'Hearn, Colin Plumb, Jon Callas and Alan Johnston and was submitted to the Internet Engineering Task Force (IETF) by Zimmermann, Callas and Johnston on March 5, 2006 and published on April 11, 2011 as . Overview ZRTP ("Z" is a reference to its inventor, Zimmermann; "RTP" stands for Real-time Transport Protocol) is described in the Internet Draft as a ''"key agreement protocol which performs Diffie–Hellman key exchange during call setup in-band in the Real-time Transport Protocol (RTP) media stream which has been established using some other signaling protocol suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zfone
is software for secure voice communication over the Internet (VoIP), using the ZRTP protocol. It is created by Phil Zimmermann, the creator of the PGP encryption software. Zfone works on top of existing SIP- and RTP-programs, but should work with any SIP- and RTP-compliant VoIP-program. Zfone turns many existing VoIP clients into secure phones. It runs in the Internet Protocol stack on any Windows XP, Mac OS X, or Linux PC, and intercepts and filters all the VoIP packets as they go in and out of the machine, and secures the call on the fly. A variety of different software VoIP clients can be used to make a VoIP call. The Zfone software detects when the call starts, and initiates a cryptographic key agreement between the two parties, and then proceeds to encrypt and decrypt the voice packets on the fly. It has its own separate GUI, telling the user if the call is secure. Zfone describes itself to end-users as a "bump on the wire" between the VoIP client and the Internet, which a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voice Over IP
Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. The terms Internet telephony, broadband telephony, and broadband phone service specifically refer to the provisioning of communications services (voice, fax, SMS, voice-messaging) over the Internet, rather than via the public switched telephone network (PSTN), also known as plain old telephone service (POTS). Overview The steps and principles involved in originating VoIP telephone calls are similar to traditional digital telephony and involve signaling, channel setup, digitization of the analog voice signals, and encoding. Instead of being transmitted over a circuit-switched network, the digital information is packetized and transmission occurs as IP packets over a packet-switched network. They transport media streams using special media delivery protoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet
The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless, and optical networking technologies. The Internet carries a vast range of information resources and services, such as the inter-linked hypertext documents and applications of the World Wide Web (WWW), electronic mail, telephony, and file sharing. The origins of the Internet date back to the development of packet switching and research commissioned by the United States Department of Defense in the 1960s to enable time-sharing of computers. The primary precursor network, the ARPANET, initially served as a backbone for interconnection of regional academic and military networks in the 1970s to enable resource shari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
