Enhanced Autocompensating Quantum Cryptography System

We have improved the hardware and software of our autocompensating system for quantum key distribution by replacing bulk optical components at the end stations with fiber-optic equivalents and implementing software that synchronizes end-station activities, communicates basis choices, corrects errors and performs privacy amplification over a local area network. The all fiber-optic arrangement provides stable, efficient and high-contrast routing of the photons. The low bit error rate leads to high error correction efficiency and minimizes data sacrifice during privacy amplification. Characterization measurements made on a number of commercial avalanche photodiodes are presented that highlight the need for improved devices tailored specifically for quantum information applications. A scheme for frequency shifting the photons returning from Alice's station to allow them to be distinguished from backscattered noise photons is also described. OCIS codes: 030.5260, 060.0060, 060.2360, 230.2240, 270.5570.Comment: 13 pages, 1 table, 9 figures; Applied Optics LP (in press, to appear 3/02

Strong Cryptography: The Global Tide of Change

Encryption technology allows people using electronic networks to ensure that the messages they send remain private--secure from hackers, industrial espionage, government wiretap abuses, and spies. Encryption technology will prove vital to the future of electronic commerce. For example, thefts of nuclear secrets from U.S. national laboratories would be much less likely if the labs' commercial software had built-in encryption features that could be used to limit unauthorized access--a type of security product discouraged by export controls. For years the U.S. government has struggled unsuccessfully to control the export of encryption technology from this country. Those ineffectual controls do, however, adversely affect the competitive position of the U.S. software industry and national security. Despite the controls, powerful encryption products are increasingly available around the world. Those products include Pretty Good Privacy, which offers 128-bit encryption, and many others. This paper provides a list of Web sites where such products may be found, thus establishing beyond doubt the futility of controls. Although some of the Web sites may from time to time disappear, others will spring up in their place

Cryptography: Mathematical Advancements on Cyber Security

The origin of cryptography, the study of encoding and decoding messages, dates back to ancient times around 1900 BC. The ancient Egyptians enlisted the use of basic encryption techniques to conceal personal information. Eventually, the realm of cryptography grew to include the concealment of more important information, and cryptography quickly became the backbone of cyber security. Many companies today use encryption to protect online data, and the government even uses encryption to conceal confidential information. Mathematics played a huge role in advancing the methods of cryptography. By looking at the math behind the most basic methods to the newest methods of cryptography, one can learn how cryptography has advanced and will continue to advance

Relay-proof channels using UWB lasers

Alice is a hand-held device. Bob is a device providing a service, such as an ATM, an automatic door, or an anti-aircraft gun pointing at the gyro-copter in which Alice is travelling. Bob and Alice have never met, but share a key, which Alice uses to request a service from Bob (dispense cash, open door, don't shoot). Mort pretends to Bob that she is Alice, and her accomplice Cove pretends to Alice that he is Bob. Mort and Cove relay the appropriate challenges and responses to one another over a channel hidden from Alice and Bob. Meanwhile Alice waits impatiently in front of a different ATM, or the wrong door, or another gun. How can such an attack be prevented?Final Accepted Versio

Photonics based perfect secrecy cryptography : toward fully classical implementations

Funding: A.D.F. acknowledges support from UK EPSRC (EP/L017008/1).Developing an unbreakable cryptography is a longstanding question and a global challenge in the internet era. Photonics technologies are at the frontline of research, aiming at providing the ultimate system capable of ending the cybercrime industry by changing the way information is treated and protected now and in the long run. Such perspective discusses some of the current challenges as well as opportunities that classical and quantum systems open in the field of cryptography as both a science and an engineering.PostprintPeer reviewe

Cryptology and Communication Security

Cryptology is the scientific study and practice of making (cryptography) and breaking (cryptanalysis) of codes andciphers. Code is a system of rephrasing parts of normal language meaningful with certain standard groups or symbols. Whereas cipher is a system of transforming fixed length group of language symbols at normally the single character of alphabet into code alphabet character. The science of making communications unintelligible to all except the intended recipient(s) is known as cryptography. Until recently cryptography has been of interest primarily to the defence and diplomatic personnel of governments, guarded over and directed by their national crypto logic services. But now a day’s It has become the part of our daily life viz. providing electronic security to our house and offices, use of ATM, Credit Card, Smart Cards and RFID tags, etc. all of them needs cryptography in some form. Private business sectors, terrorist outfit and electronic communication agencies are using cryptographic methods to keep their data, valuable information and their developmental activities secret until they feel that it is important for their commercial interest, etc. Many cryptographic devices and algorithms are available for non-governmental application, such as M209, Hagelin machine, DES, AES, Public key cryptography (RSA system), and also varieties of crypto algorithms are available in the open literatures for any interested agency to implement their own system of encryptions.Defence Science Journal, 2012, 62(1), pp.3-5, DOI:http://dx.doi.org/10.14429/dsj.62.143