“key”的概念、定义、翻译、参考文献-科学参考

key

Mathematics

In cryptography, a key is a means of encrypting the message to make the cryptogram or of decrypting the cryptogram to retrieve the message. As a simple example, a cipher permutes the 26 letters of the alphabet and a key is a rule detailing this. This is an example of a private key, and a security issue with any such system is passing such keys between correspondents.

With public key cryptography, such as RSA, the means of encrypting messages is in the public domain. This way a company allows a customer to send in an encrypted order. However, if knowledge of how to encrypt is public knowledge, then in principle so is knowledge of how to decrypt. For example, if one were given one half of an English-French dictionary, it would be possible, given enough time, to reconstruct the French-English half. For this reason encrypting with public keys has to have a computationally difficult inverse—they are one-way functions—and public keys are frequently changed to avoid being decrypted.

Computer

1. A value used to identify a member of a set. Usually the elements of the set are records (n-tuples), in which one of the fields holds the key. Variations allow multiple key fields or any field to be used as a key.
2. A value used to establish authority to access particular information. See locks and keys.
3. A value used as a basis for encryption. See cryptography.
4. See keyboard.

Internet

1 A set of characters used in the encryption of a message.
2 A unique set of characters that identify a record in a file. For example, in a file containing employee records, each employee can be associated with a unique works number which acts as a key.

Biology

A means of identifying a specimen organism by selecting from a series of choices relating to external features. Each stage in the key presents several character descriptions (two in a dichotomous key); each description is followed by a direction to another stage in the key. Selection of the character that matches the specimen leads to another stage, with another two choices, and so on until the specimen is identified.

单词	key
释义	key Mathematics In cryptography, a key is a means of encrypting the message to make the cryptogram or of decrypting the cryptogram to retrieve the message. As a simple example, a cipher permutes the 26 letters of the alphabet and a key is a rule detailing this. This is an example of a private key, and a security issue with any such system is passing such keys between correspondents. With public key cryptography, such as RSA, the means of encrypting messages is in the public domain. This way a company allows a customer to send in an encrypted order. However, if knowledge of how to encrypt is public knowledge, then in principle so is knowledge of how to decrypt. For example, if one were given one half of an English-French dictionary, it would be possible, given enough time, to reconstruct the French-English half. For this reason encrypting with public keys has to have a computationally difficult inverse—they are one-way functions—and public keys are frequently changed to avoid being decrypted. Computer 1. A value used to identify a member of a set. Usually the elements of the set are records (n-tuples), in which one of the fields holds the key. Variations allow multiple key fields or any field to be used as a key. 2. A value used to establish authority to access particular information. See locks and keys. 3. A value used as a basis for encryption. See cryptography. 4. See keyboard. Internet 1 A set of characters used in the encryption of a message. 2 A unique set of characters that identify a record in a file. For example, in a file containing employee records, each employee can be associated with a unique works number which acts as a key. Biology A means of identifying a specimen organism by selecting from a series of choices relating to external features. Each stage in the key presents several character descriptions (two in a dichotomous key); each description is followed by a direction to another stage in the key. Selection of the character that matches the specimen leads to another stage, with another two choices, and so on until the specimen is identified.
随便看	precipitation fog precipitin precisification precision precision approach radar precision inertial measurement precision(in statistics) precision(numerical analysis) precision ranging precision rectifier precocial species precognition pre-commitment precondition Precourt, Charles Jr (1955– ) precursor precursor pulse predation predator predatory pricing predator–prey equations predator–prey relationships predestination predetermination predetermined variable