Introduction to Cryptography

The role of cryptography, types of cryptographic algorithms, putting them altogether... case studies in cryptography, trust model

Introduction to Quantum Cryptography

We show in details the four quantum key distribution protocols which initiated the important field of quantum cryptography, using an accessible language for undergraduate students. We begin presenting the BB84 protocol, which uses polarization states of photons in order to transmit cryptographic keys. Thereupon we show the E91 protocol, whose security is based on the use of singlet states to generate a random sequence of bits. We end the paper with the BBM92 and the B92 protocol. These last two protocols can be seen as simplified versions of the first two.Comment: 9 pages, 2 figures, text in Portuguese, to be published in Revista Brasileira de Ensino de Fisic

Introduction to cryptography

Kriptograja je znanost koja osigurava sigurnu komunikaciju između pošiljatelja i primatelja poruke. Ljudi su kroz povijest pokušali osmisliti neslomljivu šifru. Najstarija šifra jest Cezarova, dok je prva ideja širanja bila vezana za supstituciju. Za sigurnu komunikaciju pošiljatelja i primatelja potrebno je osmisliti dobar ključ i način šifriranja poruke. Također su se kroz povijest su se stvarale mnoge naprave koje bi osigurale sigurnu komunikaciju. Postoje monoalfabetske i polialfabetske šifre. U današnje vrijeme u kojemu sve je teže osigurati zašititu podataka, ali kriptograja je dosta napredovala kao i kriptoanalitičari

RSA:dagli anni '70 al giorno d'oggi

In this note, after a brief historical excursus, we describe the revolution in cryptography of the 70es, due to the introduction of public key cryptography and the RSA algorithm. We also consider some contemporary applications of this algorithm. Modern cryptography has indeed become a commodity technology, which is currently used for applications ranging from e–commerce to digital television