Encrypted e-mail debate hots up
by Roopinder Singh
THE Internet has popularised e-mail as a fast, reliable and fairly inexpensive way of communication. There has, however, been a catch to it — it can be intercepted and read. While you might say that this is equally true of ordinary mail, there are many laws which protect the integrity of mail, though there are none that do so for the Internet, since, by its very nature, this medium takes rather unkindly to any attempts at regulation.

Science Quiz
by J. P. Garg

Laboratory on a chip
by Dipesh Satapathy

THOUGH microscale devices to process and analyse minuscule amounts of samples and reagents have for long been of interest to scientists, miniaturisation of physical and chemical processes and their integration into a single chip now seem to be a reality.

A new technology based on a device called “lab-on-a-chip” can revolutionise chemical analysis and synthesis and drug discovery in the same way microchips revolutionised computers and electronics.

The technology miniaturises chemical and physical processes and integrates them into a single microchip.

A lab-on-a-chip is a device where materials are moved around on a microchip either to mix them together for chemical reactions or to analyse them to generate information.

It can also be defined as a device on which a number of chemical processes are performed in order to go from reactants to products or from sample to analysers.

Using the technology that is mainly driven by the pharmaceutical industry, a number of analyses can be carried out in parallel on a single chip using minuscule amount of samples, according to a report in Chemical and Engineering News.

The high performance of the chips will be particularly useful for DNA-based diagnostics and finding genetic constituents in pharmaceutical and healthcare applications.

Microchip-based chemical sensing devices are already being used in portable blood analysers.

Other advantages of such chips are low manufacturing, operating and maintenance costs, low power consumption, increased precision, disposability and automation.

Current research in this field is concentrated in five areas — DNA sequencing for human and other genomic projects, screening of drugs, defence against biological and chemical weapons, clinical analysis and large-scale and economic synthesis of toxic compounds.

A typical microchip used in miniaturised chemical systems comprises a two-three-centimetres square sliver of silicon, glass, quartz or plastic that is etched with chambers and channels with cross-sections as low as 50 micrometers in length.

The chip is covered with a plate to contain the samples and reagents. Each material has its own advantages and disadvantages.

The chips are relatively bigger in size than microelectronic chips because molecules need more space than electrons.

At present, it is possible to inject volumes as low as one picolitre (millionth of a millionth of a litre) onto chips with miniaturised chemical systems.

A group of researchers from the Institute of Molecular and Biomolecuar Electronics at the University of Wales in United Kingdom has developed a method to use microchips chemical systems.

A group of researchers from the Institute of Molecular and Biomolecular Electronics at the University of Wales in United Kingdom has developed a method to use microchips for processing and assessing micro-organisms and cells.

These chips are microfactories that can diagnose infections or diseases within minutes by separating bacteria, foetal or cancer cells from blood.

These can help companies protect their customers from infectious products and contaminated water by screening supplies effectively.

California-based Hewlett-Packard and Caliper Technologies have agreed to develop “lab-on-a-chip” technology for analytical instrumentation and information systems.

Recently, a British consortium of universities and 10 companies, including Glaxo Wellcome, Kodak and Unilever launched a project to develop “lab-on-a-chip” technology.

Researchers at the Sandia National Laboratories in New Mexico are developing a tiny chemical laboratory on similar lines which uses chemical sensors built on a button-sized chip.

A group of British researchers has come out with a design wherein four DNA sample can be analysed on a single microchip. The design minimises sample handling and contamination and reduces cost.

Total analysis systems, which periodically transform chemical information into an electronic or optical signal, can also be miniaturised using glass, silicon or plastic chips. Such systems, though reliable, are bulky in conventional laboratories.

The next decade would see what dimensions would the technology, that is said to have applications in environmental maintenance, sophisticated biological analysis and synthesis of chemical processes, acquire. — PTI

Encrypted e-mail debate hots up
by Roopinder Singh

THE Internet has popularised e-mail as a fast, reliable and fairly inexpensive way of communication. There has, however, been a catch to it — it can be intercepted and read. While you might say that this is equally true of ordinary mail, there are many laws which protect the integrity of mail, though there are none that do so for the Internet, since, by its very nature, this medium takes rather unkindly to any attempts at regulation.

Our notion of privacy is rather more flexible than that of the West, though, of course, almost every one has certain messages that one would rather no one read. More than this, the growth in the popularity of the Internet has created a demand for security. Electronic mail users who desire confidentiality and sender authentication increasingly are demanding better security. The increase in the number of electronic fund transfers between banks has also increased security concerns and necessitated the use of message authentication systems, to determine if a message has originated from its proper source and to determine if there have been any modifications.

An ancient method, with many a modern application, of ensuring such privacy has been cryptography (the word dates back to 1658) which is the practice and study of encryption and decryption — encoding data so that it can only be decoded by specific individuals. A system for encrypting and decrypting data is cryptosystem.

In the context of computerised communication, this usually involves encryption — the use of an algorithm for combining the original data (plaintext, which can be read by anyone) with one or more “keys” - numbers or strings of characters known only to the sender and/or recipient. The resulting output is known as ciphertext, which is digital gibberish without the relevant key.

There are many types of data encryption, and they are the basis of network security. Common types include Data Encryption Standard and public-key encryption.

The effectiveness of cryptosystem usually depends on the secrecy of (some of) the keys rather than with the supposed secrecy of the algorithm. The longer the “key,” the more computing required to crack the code. To decipher an encrypted message by brute force, one would need to try every possible key. Computer keys are made of “bits” of information, binary units of information that can have the value of zero or one. So an eight-bit key has 256 (2 to the eighth power) possible values. A 56-bit key creates 72 quadrillion possible combinations. Given the current power of computers, a 56-bit key is considered crackable; a 128-bit key isn’t - at least not without an enormous amount of effort.

For a long time, encryption was available to nations and was out of the domain of ordinary people. With increasing computerisation, it has become easier to encrypt messages, and the use spread. Encryption technology has become easily available to both individuals and businesses, affording them a level of security formerly available practically to only military, national security, and law enforcement agencies. In fact, due to recent developments in software and hardware, some consumer-level encryption products are now so powerful that law enforcement officials say they can’t crack them, even with massive supercomputers.

The latest kid on the block is HushMail, (www.hushmail.com), a new e-mail service, promises privacy, though it is not the first Web e-mail site offering encryption. A German portal, Web.de, also offers it at its FreeMail site (http://freemail.web.de). As expected, the German interface is a bit forbidding for users not comfortable with the language. HushMail is in English, and it has defied the attempts by the US administration to control cryptography and its use. HushMail offers 1,024-bit encrypted messages that cannot be read by anyone else, according to the company. This may result in the service becoming popular, and is sure to provoke the wrath of the law enforcement officials in the USA.

In order to understand the importance of HushMail, we have to go back in time to 1976 when Diffie and Hellman introduced the use of public-key encryption, which proved quite popular. In such a system, each person gets a pair of keys, called the public key and the private key. Each person’s public key is published while the private key is kept secret. Messages are encrypted using the intended recipient’s public key and can only be decrypted using his private key.

The need for sender and receiver to share secret information (keys) via some secure channel is eliminated: all communications involve only public keys, and no private key is ever transmitted or shared. Public-key encryption has been a favoured method used on the Internet for authentication (digital signatures), confidentiality, integrity and non-repudiation. It is, however, considered cumbersome by some.

Philip Zimmermann’s free software called Pretty Good Privacy (PGP), which can encode ordinary e-mail was another milestone in publicly available encryption. PGP uses 128-bit encoding keys. Though it won the programmer accolades from the computing community, when he introduced it in 1991, it got him into trouble with the US Department of Justice which launched a three-year criminal investigation against him because US export laws allowed only 40-bit encryption to cross the national borders. Anything stronger was classified munition, just like guns and warheads. Incidentally, the laws are not so stringent in other parts of the world, including Europe.

Along with the increasing use of cryptography is the rise in concern about its possible misuse. This has brought out a familiar debate on the balance between public safety/ national security and personal freedom.

Law enforcement officials have raised concern about the possible use of such technology by tech-savvy criminals, and would thus like to keep control over encryption technologies. On the other hand, civil liberty advocates argue that such restrictions infringe on the users’ right to personal freedom and computer privacy.

So we have a phenomenon being looked at as good and bad at the same time. In his search for that which is good in itself, the German philosopher Immanuel Kant looked at various options, including intelligence, which seemed desirable as a good in itself, was not so in the hands of a scoundrel.

The debate will go on, so will the need for privacy, as well as the need to keep a check on illegal activities. The Internet is full of documents from various people taking divergent positions. This will always remain the strength of the medium.

Science Quiz
by J. P. Garg

1. This Polish astronomer strongly disagreed with the then prevalent ideas about the universe and wrote the epoch-making book “On the Revolutions of the Heavenly Spheres” which was published on the day of his death. Name the astronomer and state his contribution to astronomy.

2. An Indian scientist K.R. Sridhar and his team working in the USA have recently achieved a path-breaking feat in the field of chemistry that could make human settlements on Mars a reality. What is this feat?

3. As an object moves away from us, its apparent size becomes shorter. What determines the apparent size of the object observed by us?

4. A technique called ESWL is generally used to break stones in the kidney. What does ESWL stand for? Which type of waves are used in this technique?

5. Ecosystem diversity and species diversity are two levels of biodiversity. Can you name the third?

6. The “cloudiness” in a liquid like water due to the presence of suspended particles is used as an indicator of pollution in the liquid. What is this indicator called? Name the instrument and the unit used to measure it.

7. This abrasive material is often called inorganic graphite but unlike graphite, it is a non-conductor of electricity. Still it is widely used in electrical industry because of its high thermal conductivity. What is the chemical name of this material?

8. Baking powder is generally used for baking biscuits, cakes etc. Which chemicals does it usually contain and how does it make the dough or cake mixture swell and thus soft?

9. One problem in designing a high speed vehicle is to change its shape and contours to reduce the air drag to a minimum when it moves at high speed. What is this type of designing called?

10. National Institute of Pharmaceutical Education and Research is the biggest institute of its kind in India. Where is it located?

ANSWERS

1. Nicolas Copernicus; he postulated that the sun and not the earth was the centre of the solar system 2. Conversion of carbon dioxide (available in abundance at the Mars) into oxygen 3. Angle subtended by the object at the eye called visual angle 4. Extracorpeal Shock Wave Lithotripsy; ultrasonic waves 5. Genetic diversity 6. Turbidity; turbidometer; JTU (Jackson turbidity unit) 7. Boron nitride, BN 8. Sodium bicarbonate and tartaric acid which produce bubbles of carbon dioxide gas on being heated 9. Streamlining 10. SAS Nagar (Mohali).

Thinnest notebook
The thinnest and lightest notebook computer, the two piece Pedion EM is 1.8 inches thick and weighs 6.3 pounds. It’s half that without its Multimedia Pack, which houses a 24XCD-ROM, stereo speakers, full-size ports, and a floppy drive. The notebook has a 266MHz Pentium II processor, 4.3GB hard drive, and 12.1-inch SVGA active matrix display. Price $ 4,000. (Popular Science)

Reusable software from Germany
Investing time and money for developing customised software that can be used for only one purpose is soon going to be a thing of past as German scientists have developed a method to make software reusable.

Called product line software engineering (PuLSE), the method focuses on two major points. The first is an intensive analysis of the domain of application involving existing and planned software products. The second is the development of a standardised products platform to accomodate different software components.

Developed by scientists of Fraunhofer Establishment for Experimental Software Engineering at Kaiseralautern, the platform functions as a reference architecture allowing software to be reused.

All that remains to be done is to decide which of the options are of relevance to the product and which are not.

New method to make tablets

A new method of tableting pharmaceuticals has been developed by Japanese researchers.

The method, developed by researchers of Kyowa Hokko Kogyo Company uses a new device called external lubrication system (EXLUB) to produce tablets in a versatile and simple way, reports Science and Techonology in Japan.

Tablets are compacted by a tableting machine from the mixture of an active ingredient with a binding agent (a substance which serves as an adhesive to bind the main ingredient and other components in tablets) and an excipient (a substance which is added to make the drug easy to take).

Converting sludge into board

A recycling process that can be used both for converting plant residues into construction boards and for making brick has been developed by scientists at Salford University in England.

The process involves collecting the waste material in single tank with an agent to bring together the fine particles of the solution to form flocs. The flocculating agent assists dewatering.

The Salford researchers have found that when the fibre-rich streams are collected separately and used for board making, the sludge left behind can be used for brick making. The clay is mainly white china.

New railway track design

German researchers have come up with a new kind of railway track design that is easy to maintain and lasts longer.

Traditional railway tracks on ballast display a tendency to oscillate which is a problem at high speed. The routes too have to be maintained on an ongoing basis.

Regular clearance of weeds that sprout through open spaces in the tracks is also needed as the roots of weeds can affect the stability of the trackbed, reports the German Newsletter DFD.

Researchers of German track manufacturers Cronau and Soar have developed a new wide track design in which the ballast trackbed is almost completely covered by concrete sleepers. The ballast between the sleepers thus becomes superfluous and the open space out of which the weeds can sprout is thus reduced to a minimum.