Plaintext or Cleartext : Text that can be understood without any special measures in called Plaintext or Cleartext.
Encryption : The method of disguising plaintext in such a way as to hide it's substance is called Encryption. And that text is called Ciphertext.
Decryption : The process of reverting ciphertext is called Decryption.
Cryptography : is the science of using mathematics to encrypt and decrypt data. Cryptanalysis : is the science of analysing and breaking secure communications. * Cryptanalysts are also called as attackers.
“There are two kinds of cryptography in this world: cryptography that will stop your kid sister from reading your files, and cryptography that will stop major governments from reading your files. This book is about the latter.”
Cryptography can be strong or weak, as explained above. Cryptographic strength is measured in the time and resources it would require to recover the plaintext. The result of strong cryptography is ciphertext that is very difficult to decipher without possession of the appropriate decoding tool. How difficult? Given all of today’s computing power and available time—even a billion computers doing a billion checks a second—it is not possible to decipher the result of strong cryptography before the end of the universe. One would think, then, that strong cryptography would hold up rather well against even an extremely determined cryptanalyst. Who’s really to say? No one has proven that the strongest encryption obtainable today will hold up under tomorrow’s computing power. However, the strong cryptography employed by PGP is the best available today. Vigilance and conservatism will protect you better, however, than claims of impenetrability.