CRYPTOGRAPHY.docx - CRYPTOGRAPHY Cryptography is the science of writing in secret code and is an ancient art the first documented use of cryptography in

CRYPTOGRAPHY.docx - CRYPTOGRAPHY Cryptography is the...

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CRYPTOGRAPHY Cryptography is the science of writing in secret code and is an ancient art; the first documented use of cryptography in writing dates back to circa 1900 B.C. when an Egyptian scribe used non-standard hieroglyphs in an inscription. Some experts argue that cryptography appeared spontaneously sometime after writing was invented, with applications ranging from diplomatic missives to war-time battle plans. It is no surprise, then, that new forms of cryptography came soon after the widespread development of computer communications. In data and telecommunications, cryptography is necessary when communicating over any untrusted medium, which includes just about any network, particularly the Internet. There are five primary functions of cryptography today: Confidentiality Confidentiality is the fundamental security service provided by cryptography. It is a security service that keeps the information from an unauthorized person. It is sometimes referred to as privacy or secrecy . Confidentiality can be achieved through numerous means starting from physical securing to the use of mathematical algorithms for data encryption. Data Integrity It is security service that deals with identifying any alteration to the data. The data may get modified by an unauthorized entity intentionally or accidently. Integrity service confirms that whether data is intact or not since it was last created, transmitted, or stored by an authorized user. Data integrity cannot prevent the alteration of data, but provides a means for detecting whether data has been manipulated in an unauthorized manner. Authentication Authentication provides the identification of the originator. It confirms to the receiver that the data received has been sent only by an identified and verified sender. Authentication service has two variants − Message authentication identifies the originator of the message without any regard router or system that has sent the message. Entity authentication is assurance that data has been received from a specific entity, say a particular website. Apart from the originator, authentication may also provide assurance about other parameters related to data such as the date and time of creation/transmission. Non-repudiation 1
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It is a security service that ensures that an entity cannot refuse the ownership of a previous commitment or an action. It is an assurance that the original creator of the data cannot deny the creation or transmission of the said data to a recipient or third party. Non-repudiation is a property that is most desirable in situations where there are chances of a dispute over the exchange of data. For example, once an order is placed electronically, a purchaser cannot deny the purchase order, if non-repudiation service was enabled in this transaction.
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  • Spring '16
  • Magu
  • Cryptography, Public-key cryptography, Pretty Good Privacy

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