《科技英语文献阅读与翻译》 Unit 1-TextB
cryptography
Cryptography is the study of mathematical techniques related to aspects of information security such as confidentiality, data integrity, entity authentication, and data origin authentication.
Hash functions are employed in symmetric and asymmetric encryption systems and are used to calculate a fingerprint/imprint of a message or document.
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Text B Digital Signature in Applied Cryptography
hash function and hash value
When hashing a message, the message is converted into a short bit string--a hash value-and it is impossible to re-establish the original message from the hash value.
A hash value is unique in the sense that two messages cannot result in the same bit string, and any attempt to make changes to the message will negate the value and thus the signature.
Hash Function is an algorithm that transforms a string of characters into a usually shorter value of a fixed length or a key that represents the original value. This is called the hash value.
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Text B Digital Signature in Applied Cryptography
digital cash
Digital cash is a digitally signed payment message that serves as a medium of exchange. Digital cash is a system of purchasing cash credits in relatively small amounts, storing the credits in your computer, and then spending them when making electronic purchases over the Internet.
private key
It is the key for use with asymmetric encryption that is accessible to the key holder only. Asymmetric encryption uses different keys for encryption and decryption. Each participant is assigned a pair of keys, consisting of an encryption key and a corresponding decryption key.
As the Internet and other forms of electronic communication become more prevalent, electronic security is also becoming increasingly important. Cryptography is used to protect e-mail messages, credit card information, and corporate data.
The public key can be certified using an electronic certificate issued and signed by a certification authority.
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Text B Digital Signature in Applied Cryptography
A private key is used for generating digital signatures and for decrypting data.
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Text B Digital Signature in Applied Cryptography
hash function and ha One
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Text B Digital Signature in Applied Cryptography
public key
It is the key for use with public key encryption methods that is publicly made available. It is published by the key holder or the issuing certification authority. The certification authority’s directory server can distribute it by disk, web download or e-mail.