Cryptography: introduction, basic concepts, cryptographic protocols, algorithms, digital signatures, digital certificates. Symmetric and asymmetric encryption algorithms, hash functions, key exchange. Cryptographic standards. PKI infrastructure: key management, establishment of PKI, certificate authorities, hierarchy of certificate authorities. Security of XML documents: digital signatures, encryption, web services security. Smart card technology: organization, standards and use. Application of security concepts at the level of operating systems, databases, and computer networks. Authentication: single-factor authentication, two-factor authentication, passwords, challenge-response principle, attacks, Kerberos, HTTP authentication. Access control: concepts, elements, policies, mechanisms and models of access control. Threat modeling.