Hardware Devices
Those have to be acquired and installed by the user. For example under a debit card approach, the user purchases a debit card that is pre-loaded with a certain amount of value. After installation, the debit card is debited automatically as the user consumes copyrighted works.
Digital Certificates
Hereby a certification authority issues to a user an electronic file that identifies the user as the owner of a public key. Those digital certificates, besides
Centralized Computing
Under this approach all of the executables remain at the server. Each time the executable is used, the user's computer must establish contact with the server, allowing the central computer to meter access.
Access Codes
Access code devices permit users to "unlock" protective mechanisms (e.g. date bombs or functional limitations) embedded in copyrighted works. Copyright owners can meter the usage of their works, either by unlocking the
Copyright Clearinghouses
Under this approach copyright owners would commission "clearinghouses" with the ability to license the use of their works. A user would pay a license fee to obtain rights concerning the intellectual property.
TEXTBLOCK 1/1 // URL: http://world-information.org/wio/infostructure/100437611725/100438659615
Blowfish is a symmetric key block cipher that can vary its length.
The idea behind is a simple design to make the system faster than others.
IDEA is another symmetric-key system. It is a block cipher, operating on 64-bit plaintext blocks, having a key-length of 128 bits.
General H. Norman Schwarzkopf (* 1934) followed in his father's footsteps at the United States Military Academy at West Point.
In 1965 he applied to join the troops in Vietnam. For the next 20 years Schwarzkopf worked on his career. As Commander in Chief of the U.S. Central Command, he led U.S. and allied forces in the Gulf War (Operations Desert Shield and Desert Storm). He retired from the Army in 1992 and wrote his autobiography.
For a picture see: