History of Cryptography

Kriptografija je matematička disciplina koja proučava različite načine kriptiranja. Ona omogućuje komunukaciju izmedu dviju strana tako da treća strana ne može razumjeti poruke. Treća strana može doći do poruke presretanjem, prisluškivanjem i na neke druge načine, ali ju ne može dešifrirati bez pravog ključa. Kroz povijest, od starog vijeka pa sve do danas, kriptografija je postupno napredovala i kako je vrijeme prolazilo imala je sve pouzdanije strojeve i metode kojima se mogu šifrirati poruke. Kriptografija je bila najkorisnija u ratovima, a danas ima veliku primjenu u sigurnosti raznih sustava. Na samom početku kriptiranja korišteni su ukrasni simboli, zatim kvadrati koji su sadržavali slova abecede te prvi i najjednostavniji uredaj - obični štap (skytale). Nakon toga pojavljuje se šifrarnik s kotačem, sustav s dva diska, Playfairov i drugi sustavi, dok se u 20. stoljeću razvijaju elektromehanički strojevi Enigma i Sigaba. U novije vrijeme pojavljuju se kriptografski algoritmi kao što su, primjerice, DES, AES, RSA, NTRU i ECC, a sve se više razvija i kvantna kriptografija.Cryptography is a mathematical discipline that studies different ways of encryption. It actually allows communication between two sides so that a third side can not understand the message. Third side can get to the message by intercepting, eavesdropping and in some other ways, but it can not be decrypted without the right key. Throughout history, from Antiquity to present day, cryptography has progressively advanced and as time went on, it had more reliable machines and methods used to encrypt certain messages. Cryptography has been most useful in wars and today has extensive application in various security systems. At the beginning of encryption were used hieroglyphics, then squares containing letters of the alphabet and the first and the most simple device - ordinary stick (skytale). After that appears a codebook with a wheel, a system with two discs, Playfair and other systems, while in the 20th century were developed electromechanical machines Enigma and Sigaba. In recent years, appears cryptographic algorithms such as, for example, DES, AES, RSA, NTRU and ECC, and has been further developed and quantum cryptography