Cryptography is an indispensable tool for protecting information in computer systems. Cryptography or Cryptology (from Ancient Greek: kryptós "hidden, secret"; and graphein, "to write", or logia, "study", respectively is the practice and study of techniques for secure communication in the presence of third parties called adversaries. More generally, cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages; various aspects in information security such as data confidentiality, data integrity, authentication, and non-repudiation are central to modern cryptography. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, electrical engineering, communication science, and physics. Applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications.

System security encompasses all facets of accessing information assets. From authentication, to software updates, anti-virus protection, and modifications - security is a key component to a device operating at its optimum. The objective of system security is the protection of information and 
property from theft, corruption and other types of damage, while allowing the information and property to remain accessible and productive. System security includes the development and implementation of security countermeasures.