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Asymmetric or Public-Key-Cryptosystems 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. |
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Extract of Disney’s Content Production and Distribution Holdings Although the traditional media companies first steps into the digital sphere were fairly clumsy, they have quickly learned from their mistakes and continued to enlarge their Internet presence. During the last years many of the smaller players in the field of digital media have been driven out of competition by the huge media conglomerates. This mainly is a result of the advantages that the commercial media giants have over their less powerful counterparts:
Commercial media companies have close and long ties to advertisers, which enables them to seize most of these revenues. |
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Sperry Formerly (1955 - 1979) Sperry Rand Corporation, American corporation that merged with the Burroughs Corporation in 1986 to form Unisys Corporation, a large computer manufacturer. |
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Division of labor The term refers to the separation of a work process into a number of tasks, with each task performed by a separate person or group of persons. It is most often applied to |
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Leitrim Station Latitude: 45.33, Longitude: -75.6 At Canadian Forces Station Leitrim collection of foreign signals intelligence is collected. Foreign radio, radar and other electronic emissions are intercepted and analyzed to provide foreign intelligence to the Canadian government. Leitrim contains a wide variety of antennae, including a Pusher HF-DF circularly-disposed antenna array (CDAA), three other large circular arrays, four satellite dishes, and a number of other, small antennae. The targets of Leitrim's dishes are probably Mexican and/or Brazilian communications satellites. Both countries' satellite constellations were established in 1985, at about the same time as Leitrim's new dishes started to be installed. A focus on these satellites would also explain CSE's rumoured increase in Spanish language activities. Source: |
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