Here the keys for encryption and decryption differ. There needs to exist a private key, which is only known to the individual, and a public key, which is published. Every person has her or his own private key that is never published. It is used for decrypting only. Mathematically the different keys are linked to each other, still it is nearly impossible to derive the private key from the public one.
For sending a message to someone, one has to look up the other's public key and encrypt the message with it. The keyholder will use his/her private key to decrypt it. While everybody can send a message with the public key, the private key absolutely has to stay secret - and probably will.
"The best system is to use a simple, well understood algorithm which relies on the security of a key rather than the algorithm itself. This means if anybody steals a key, you could just roll another and they have to start all over." (Andrew Carol)
very famous examples for public-key systems are:
· RSA:
The RSA is probably one of the most popular public-key cryptosystems. With the help of RSA, messages can be encrypted, but also digital signatures are provided.
The mathematics behind are supposedly quite easy to understand (see:
· PGP:
PGP is a public key encryption program. Most of all it is used for e-mail encryption.
It is supposed to be quite safe - until now.
· PGPi is simply the international variation of PGP.
for further information about the RSA and other key-systems visit the RSA homepage:
or:
All of those tools, like hash functions, too, can help to enhance security and prevent crime.
They can theoretically, but sometimes they do not, as the example of the published credit card key of France in March 2000 showed.
For more information see:
Still, cryptography can help privacy.
On the other hand cryptography is only one element to assure safe transport of data. It is especially the persons using it who have to pay attention. A key that is told to others or a lost cryptographic key are the end of secrecy.
TEXTBLOCK 1/3 // URL: http://world-information.org/wio/infostructure/100437611776/100438659074
Another important multilateral treaty concerned with
The complete TRIPS agreement can be found on:
TEXTBLOCK 2/3 // URL: http://world-information.org/wio/infostructure/100437611725/100438659758
4th millennium B.C.
In Sumer
Writing and calculating came into being at about the same time. The first pictographs carved into clay tablets were used for administrative purposes. As an instrument for the administrative bodies of early empires, which began to rely on the collection, storage, processing and transmission of data, the skill of writing was restricted to only very few. Being more or less separated tasks, writing and calculating converge in today's computers.
Letters are invented so that we might be able to converse even with the absent, says Saint Augustine. The invention of writing made it possible to transmit and store information. No longer the ear predominates; face-to-face communication becomes more and more obsolete for administration and bureaucracy. Standardization and centralization become the constituents of high culture and vast empires as Sumer and China.
3200 B.C.
In Sumer the seal is invented.
About 3000 B.C.
In Egypt papyrus scrolls and
About 1350 B.C.
In Assyria the cuneiform script is invented.
1200 B.C.
According to Aeschylus, the conquest of the town of Troy was transmitted via torch signals.
About 1100 B.C.
Egyptians use homing pigeons to deliver military information.
TEXTBLOCK 3/3 // URL: http://world-information.org/wio/infostructure/100437611796/100438659725
Claude Chappe built a fixed optical network between Paris and Lille. Covering a distance of about 240kms, it consisted of fifteen towers with semaphores.
Because this communication system was destined to practical military use, the transmitted messages were encoded. The messages were kept such secretly, even those who transmit them from tower to tower did not capture their meaning, they just transmitted codes they did not understand. Depending on weather conditions, messages could be sent at a speed of 2880 kms/hr at best.
Forerunners of Chappe's optical network are the
For more information on early communication networks see
KMI is the leading source for information on fiber-optics markets. It offers market research, strategic analysis and product planning services to the opto-electronics and communications industries. KMI tracks the worldwide fiber-optic cable system and sells the findings to the industry. KMI says that every fiber-optics corporation with a need for strategic market planning is a subscriber to their services.
RTMark is a group of culture jammers applying a brokerage-system that benefits from "limited liability" like any other corporation. Using this principle, RTMark supports the sabotage (informative alternation) of corporate products, from dolls and children's learning tools to electronic action games, by channelling funds from investors to workers. RTMark searches for solutions that go beyond public relations and defines its "sbottom line" in improving culture. It seeks cultural and not financial profit.