What Is Information Security?

Information security is the practice of protecting information and information systems from unauthorized access, use, disclosure, disruption, modification, or destruction. According to the NIST Computer Security Resource Center, the field is organized around three core objectives derived from the CIA triad: confidentiality (restricting access to authorized parties), integrity (preventing improper modification or destruction), and availability (ensuring timely, reliable access). Together these three properties define the security posture of any system or dataset, and the engineering task is to implement technical, administrative, and physical controls that uphold all three simultaneously.

Information security encompasses both technical controls and governance frameworks. On the technical side it draws on cryptography, network engineering, operating system design, and formal verification. On the governance side it draws on risk management, policy development, and compliance management. Information assurance, a closely related concept in government and military contexts, extends the definition to include authentication, non-repudiation, and the resilience of mission-critical systems under adversarial conditions. The IEEE, through its publications and the IEEE Security and Privacy journal, covers the full breadth of research across these domains.

Network and Internet Security

Network security addresses the controls that protect data in transit and defend the infrastructure through which that data flows. Firewalls, intrusion detection and prevention systems, virtual private networks (VPNs), and transport layer security (TLS) are among the core mechanisms. Internet security extends these concerns to the open, adversarially complex environment of the public internet, where threats include distributed denial-of-service (DDoS) attacks, phishing campaigns, and traffic interception. Protocol-level defenses such as DNSSEC (DNS Security Extensions) and BGP route origin validation help harden the routing infrastructure that the internet depends on. The NIST Cybersecurity Framework, first published in 2014 and updated to version 2.0 in 2024, provides an internationally adopted risk management structure covering identification, protection, detection, response, and recovery across networked environments.

System and Software Security

System security addresses the protection of computing platforms, operating systems, and the applications that run on them. Secure software development practices, including threat modeling, static analysis, and fuzz testing, aim to eliminate vulnerabilities before deployment. Runtime protections such as address space layout randomization (ASLR), stack canaries, and control-flow integrity mitigate the impact of residual vulnerabilities. Operating system access controls govern which processes and users can read or modify files, network sockets, and hardware resources. The Common Vulnerabilities and Exposures (CVE) system, maintained by MITRE and supported by the NIST National Vulnerability Database, provides a standardized catalog of publicly known vulnerabilities that security teams use to prioritize patching and remediation.

Privacy and Trust

Privacy and trust concerns overlap with but extend beyond the classical CIA triad. Differential privacy, a mathematical framework formalized by Dwork et al. in 2006, provides quantifiable guarantees that the release of aggregate statistical results does not expose individual-level information. It has been adopted in production systems by organizations including Apple, Google, and the U.S. Census Bureau for the 2020 decennial count. Trust models in distributed systems address the question of how much confidence a party should place in an unknown or partially known peer, informing the design of public key infrastructure (PKI), certificate transparency, and zero-trust architecture, which eliminates the assumption that devices inside a network perimeter can be trusted by default.

Applications

Information security has applications in a wide range of fields, including:

• Financial services, where regulatory requirements such as PCI-DSS mandate specific controls for payment card data
• Critical infrastructure protection, including grid security for electric power networks exposed to cyber-physical threats
• Healthcare, where patient data protection is mandated under HIPAA and equivalent national regulations
• Cloud computing, where shared-responsibility models define which security obligations belong to the provider and which to the customer
• Government and defense, where classified information systems require accreditation under frameworks such as NIST SP 800-53 and the Risk Management Framework