Data Protection and Security

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Introduction To Cryptography

I.I

Cryptography and Its Applications

Cryptography

Cryptography is the art and science of encryption, converting information from its normal form to an incomprehensible format. At least, that is how it started out. Nowadays, it is much broader, covering authentication, digital signatures, and many more elementary security functions.

Cryptography is an extremely varied field. From quantum physics to DNA computing, there are so many scientific disciplines in relation with cryptography. Hence there is nobody in the world who knows everything about cryptography. There isn’t even anybody who knows most of it.

Cryptography by itself is fairly useless. It has to be part of a much larger system. Cryptography is like a “lock” in the physical world. A lock by itself is singularly useless thing. Even though cryptography is only a small part of the security system, it is a very critical part. Cryptography takes on the role of the lock: it has to distinguish between “good” access and “bad” access. This is much more difficult than keeping everybody out.