السلام عليكم :
هذه اول مشالركة لي, و انا فخور ان اكون عضو في هذا النتدى الحبيب. لن ازيد على ما قاله المبدع الاستاذ ياسر . . س
اشرح الفرق بالانجليزي (اعذروني)
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First of all I need to define three terms in Securiy
- Authentication: The assurance that the communicating entity is the one that it claims to be.
example: Alice Send Bob a message, Authentication assure that this message received to Bob has sent from Alice not any one else.
- Confidentiality : The protection of data from unauthorized disclosure.
Example: Alice send Bob an encrypted message, Confidential satisfy that only Bob can decrypt this message
- Integrity: The assurance that data received are exactly as sent by an authorized entity
Example: Alice send a message to Bob, Integrity will assure that the message has not been modified (delete, insert, ...)
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Encryption Vs Hashing:
Encryption: also called "Encipherment", The use of mathematical algorithms to transform data into a form that is not readily intelligible.
Two main Encryption Algorithms:
1- Symmetric Encryption : Same key is used to encrypt and decrypt the message
Symeetric encryption can provide Confidentiality (if used alone)
Example of Symmetric : DES, and AES
2- Asymmetric Encryption: Two different keys are used (Public and Private keys). Encrypt the message with one key and decrypt the message with the other key.
Example of Asymmetric: RSA
Asymmetric Encryption provice Confidentiality and Authemtication.
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Hash Funtion:
provide a tool to test the integrity of messages. A hash function takes an arbitrarily long message as input and produces, a generally much shorter, fixed length string, called hash value.
Steps to use the hash function
1-Alice want to send a Message M to Bob,
2-Alice will hash the message to produce hash value H ==>[ H = h(M)]
3- Alice will append the hash value H to the message and send them to Bob
4- Bob will receivce the message and the hash value
5-Bob will use the same hash function and hash the message
6- if the hash value is same as the one received then the message has not changed.
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