Information Security Resources

Entries Tagged ‘decryption’

Firewall: The Realization of a Company’s Internet and Network Access Policy

The original definition of a firewall is: “a partition made of fireproof material to prevent the spread of a fire from one part of a building or ship to another or to isolate an engine compartment, as on a plane, automobile, etc.” 1 Today, in the computer world, the term refers to any piece of […]

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Cryptography – Revisited

Cryptography, or cryptology, derived from the Greek words for “hidden” writing or speaking, is the practice and study of hiding information. Until modern times, cryptography referred almost exclusively to encryption, the process of converting ordinary information (plain text) into unintelligible gibberish (confidentiality). Cryptography is now considered to be a branch of both mathematics and computer […]

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Polyalphabetic Substitution Encryption

What can be improved so that the the susceptibility to frequency analysis attack problems of alphabetic subsitution methods like Caesar Cipher and Monalphabetic Substituion can be removed? We can use a different set of encryption mapping in the order of each alphabet encryption. Suppose we have the sentence again ATTACK STARTS ON SEVEN TONIGHT We […]

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What is Cryptography?

Cryptography is the science (or Art?) of using mathematics to encrypt and decrypt data

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