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Authentication Methods Overview

Sep 5, 2025

Overview

This lecture reviews the main authentication methods used in information systems, covering their concepts, strengths, weaknesses, and future trends, with a focus on biometrics and keystroke dynamics.

Key Concepts of Authentication

  • Identification, authentication, and authorisation are separate but related steps in security systems.
  • Authentication confirms that a user is who they claim to be, using proofs like passwords or biometrics.
  • Authorisation determines what resources or operations an authenticated user may access.
  • The authentication process involves enrolment (user registration), selection of channel (secure/insecure), and verification steps.

Authentication Factors

  • Four main authentication factors: something the user knows (password), owns (token), is (biometric), or does (gesture).
  • A fifth factor can be location or time (“somewhere the user is”).
  • Using multiple factors (multi-factor authentication) can increase security but may also impact usability.

Common Authentication Methods

  • Static authentication by shared secret: Most common; uses passwords or PINs but is vulnerable to theft, replay, and guessing attacks.
  • One-time password (OTP) tokens: Generate a new password for each use; protect against replay attacks but require synchronization.
  • Cryptographic challenge-response: Proves knowledge of secret without sending it; strong security but may require expensive infrastructure.
  • Radio Frequency Identification (RFID): Used for item identification and access control; susceptible to wireless attacks if not combined with additional protection.
  • Biometrics: Uses physical or behavioral traits for authentication (fingerprints, face, keystroke dynamics, etc.); strong link to user but raises privacy and permanence issues.

Biometrics and Keystroke Dynamics

  • Biometrics divided into morphological, behavioral, and biological traits.
  • Keystroke dynamics analyzes individual typing patterns as a behavioral biometric.
  • Advantages: difficult to copy, low cost for behavioral biometrics like keystroke dynamics.
  • Limitations: enrollment complexity, possible errors, variability between authentications, and privacy concerns.
  • Soft biometrics use non-unique traits (e.g., gender, age) to complement standard biometrics.

Comparative Analysis of Methods

  • Simpler methods (like passwords) are more popular and easier to use but less secure.
  • Stronger methods (biometrics, challenge-response) offer higher security but cost more and may face acceptance issues.
  • No single method fits all needs; usability and acceptance are critical for successful deployment.

Future Trends and Conclusions

  • Emphasis on stronger, user-friendly authentication, especially biometric-based solutions.
  • Keystroke dynamics is promising due to low cost and minimal hardware requirements.
  • Passwords are increasingly seen as inadequate alone, but all methods have trade-offs between security, cost, and usability.
  • Privacy concerns and the potential for biometric data theft require continued innovation.

Key Terms & Definitions

  • Authentication — The process of verifying an entity’s identity.
  • Authorisation — Granting access rights to authenticated users.
  • Enrolment — Registration step where user credentials or biometrics are captured.
  • One-time password (OTP) — A password valid for only one login session or transaction.
  • Challenge-response — Authentication method where the system asks a question and expects a valid answer based on a secret.
  • Biometrics — Authentication using unique physical or behavioral traits.
  • Keystroke dynamics — Biometric authentication based on the way a person types.
  • Soft biometrics — Traits like gender or age used to supplement primary biometric data.

Action Items / Next Steps

  • Review the strengths and weaknesses of each authentication method.
  • Consider usability and security when selecting an authentication approach.
  • Read more about soft biometrics and keystroke dynamics for future assignments.