Authentication Methods Explained: Passwords, Biometrics, and Tokens

IB students should explain that passwords are convenient but vulnerable.

Biometric Authentication

Biometric authentication relies on:

• Something the user is

Common biometric methods include:

• Fingerprints
• Facial recognition
• Iris or retina scans

How Biometrics Work

• Physical traits are scanned
• Compared against stored biometric data

Advantages

• Difficult to copy or share
• Convenient for users
• No need to remember secrets

Disadvantages

• Privacy concerns
• False positives or false negatives
• Cannot be changed if compromised

IB examiners often expect students to mention privacy risks.

Token-Based Authentication

Token-based authentication relies on:

• Something the user has

Examples include:

• Key cards
• One-time password generators
• Mobile authentication apps

How Tokens Work

• The user possesses a physical or digital token
• The system verifies the token’s value

Advantages

• Harder to steal remotely
• Reduces reliance on memory

Disadvantages

• Tokens can be lost or stolen
• Additional cost
• Requires extra devices

Tokens are commonly used in secure systems.

Multi-Factor Authentication (MFA)

Many systems combine methods using multi-factor authentication.

MFA requires:

• Two or more authentication factors

For example:

• Password + fingerprint
• Password + one-time code

MFA significantly improves security by reducing reliance on a single method.

Comparing Authentication Methods

Strong IB answers compare methods clearly:

• Passwords: convenient but vulnerable
• Biometrics: secure but raise privacy issues
• Tokens: secure but require physical possession

No single method is perfect.

Choosing the Right Method

The best authentication method depends on:

• Security requirements
• User convenience
• Cost
• Privacy concerns

High-security systems often use MFA.

Common Student Mistakes

Students often:

• Confuse authentication with authorisation
• Ignore disadvantages
• Assume biometrics are flawless
• Forget MFA

Balanced evaluation earns higher marks.

How This Appears in IB Exams

IB questions may ask students to:

• Explain an authentication method
• Compare different methods
• Justify a choice for a scenario
• Discuss strengths and weaknesses

Explanation matters more than memorisation.

Final Thoughts

Authentication confirms a user’s identity using passwords, biometrics, tokens, or a combination of methods. Each approach has strengths and weaknesses, and secure systems often use multiple factors.

Understanding authentication methods allows IB Computer Science students to explain access control systems clearly and confidently — exactly what examiners expect.

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