Most computer systems are far from being secure.
A lack of security - it is said - might hinder the developments of new information technologies. Everybody knows electronic transactions involve a more or less calculated risk. Rumors about insecurity let consumers doubt whether the commodity of e-commerce is bigger or its risks. First of all the market depends on the consumer's confidence. To provide that another application for public key cryptography gets essential: the digital signature, which is used to verify the authenticity of the sender of certain data.
It is done with a special private key, and the public key is verifying the signature. This is especially important if the involved parties do not know one another. The DSA (= Digital Signature Algorithm) is a public-key system which is only able to sign digitally, not to encrypt messages. In fact digital signature is the main-tool of cryptography in the private sector.
Digital signatures need to be given for safe electronic payment. It is a way to protect the confidentiality of the sent data, which of course could be provided by other ways of cryptography as well. Other security methods in this respect are still in development, like digital money (similar to credit cards or checks) or digital cash, a system that wants to be anonymous like cash, an idea not favored by governments as it provides many opportunities for money laundry and illegal transactions.
If intellectual property needs to be protected, a digital signature, together with a digital timestamp is regarded as an efficient tool.
In this context, the difference between identification and authentication is essential. In this context smartcards and firewalls are relevant, too.
A lot of digital transactions demand for passwords. More reliable for authentication are biometric identifiers, full of individual and unrepeatable codes, signatures that can hardly be forged.
For more terms of cryptography and more information see:
TEXTBLOCK 1/2 // URL: http://world-information.org/wio/infostructure/100437611776/100438659015
1455
Gutenberg's printing press was an innovative aggregation of inventions known for centuries before Gutenberg: the olive oil press, oil-based ink, block-print technology, and movable types allowed the mass production of the movable type used to reproduce a page of text and enormously increased the production rate. During the Middle Ages it took monks at least a year to make a handwritten copy of a book. Gutenberg could print about 300 sheets per day. Because parchment was too costly for mass production - for the production of one copy of a medieval book often a whole flock of sheep was used - it was substituted by cheap paper made from recycled clothing of the massive number of deads caused by the Great Plague.
Within forty-five years, in 1500, ten million copies were available for a few hundred thousand literate people. Because individuals could examine a range of opinions now, the printed Bible - especially after having been translated into German by Martin Luther - and increasing literacy added to the subversion of clerical authorities. The interest in books grew with the rise of vernacular, non-Latin literary texts, beginning with Dante's Divine Comedy, the first literary text written in Italian.
Among others the improvement of the distribution and production of books as well as increased literacy made the development of print mass media possible.
Michael Giesecke (Sinnenwandel Sprachwandel Kulturwandel. Studien zur Vorgeschichte der Informationsgesellschaft, Frankfurt am Main: Suhrkamp, 1992) has shown that due to a division of labor among authors, printers and typesetters Gutenberg's invention increasingly led to a standardization of - written and unwritten - language in form of orthography, grammar and signs. To communicate one's ideas became linked to the use of a code, and reading became a kind of rite of passage, an important step towards independency in a human's life.
With the growing linkage of knowledge to reading and learning, the history of knowledge becomes the history of reading, of reading dependent on chance and circumstance.
For further details see:
Martin Warnke, Text und Technik,
Bruce Jones, Manuscripts, Books, and Maps: The Printing Press and a Changing World,
TEXTBLOCK 2/2 // URL: http://world-information.org/wio/infostructure/100437611796/100438659777
David Kahn can be considered one of the most important historians on cryptography. His book The Codebreakers. The comprehensive history of secret Communication from Ancient Times to the Internet, written in 1996 is supposed to be the most important work on the history of cryptography.