What is the difference between authentication, authorization, and identification?
Junior
What are the core components of IAM?
Junior
What is the AAA (Authentication, Authorization, Accounting/Audit) framework in security?
Junior
What are the core objectives of Identity and Access Management (IAM)?
Junior
What is Identity and Access Management (IAM)?
Junior
Why is Identity and Access Management (IAM) essential in today's era?
Junior
What are the common authentication factors (something you know, something you have, something you are)?
Junior
What is a claim in the context of identity, and how does it relate to a principal or subject?
Junior
What is user provisioning and de-provisioning in Identity and Access Management?
Mid
What is the difference between authentication and identity management?
Mid
Security Principles
Explain the principle of least privilege. Why is it a foundational security concept?
Junior
Explain the deny by default principle in authorization.
Junior
Why should authorization logic never be enforced solely on the client side?
Junior
What is coarse-grained vs. fine-grained authorization? Provide examples.
Mid
What is separation of duties, and how does it complement the principle of least privilege?
Mid
What is defense in depth, and how does it apply to authentication and authorization?
Mid
What are the benefits and challenges of implementing the principle of least privilege in large organizations?
Senior
Can you explain the confused deputy problem in access control?
Senior
What does 'fail-secure' or 'fail-closed' mean for an access-control decision, and why is it preferred over failing open?
Senior
Access Control Models
Explain Role-Based Access Control (RBAC). What are its advantages and limitations, such as role explosion?
Mid
What is the difference between role-based access control (RBAC) and attribute-based access control (ABAC), and when would you use each?
Mid
How would you implement role-based access control (RBAC)?
Mid
What are the different types of access control models (RBAC, ABAC, ACLs, MAC, DAC)? Explain their core principles.
Mid
Explain the concept of claims-based authorization.
Mid
What is the difference between discretionary (DAC) and mandatory (MAC) access control?
Mid
Explain Attribute-Based Access Control (ABAC) and the roles of PDP, PEP, and PIP.
Senior
What is Relationship-Based Access Control (ReBAC), such as the Google Zanzibar model, and when is it useful?
Senior
What is externalized authorization with a policy engine (e.g., OPA/Rego), and what are its benefits?
Senior
How do you enforce object-level or row-level authorization and tenant isolation in a multi-tenant system?
Senior
Password Security
Why do we hash passwords instead of encrypting them for storage?
Junior
What is a password encoder and why is it mandatory?
Junior
Explain password hashing, salting, and peppering. Why are adaptive hashing algorithms like bcrypt, scrypt, and Argon2 preferred over fast hashes like MD5 or SHA-1 for passwords?
Mid
What is a work factor or cost factor in password hashing, and why is it important?
Mid
Which password encoder would you use and why?
Mid
What are the arguments for and against mandatory periodic password rotation policies?
Mid
What is password entropy, and how does it relate to password strength requirements?
Mid
What is breached-password (credential) checking, and why is it recommended over complex composition rules?
Mid
Why is a timing-safe comparison important when verifying secrets or tokens?
Senior
Jwt & Tokens
What is a JSON Web Token (JWT)? Describe its structure (header, payload, signature) and the purpose of each part.
Junior
What is the role of the payload in a JWT?
Junior
Why should you avoid putting sensitive data in a JWT payload?
Junior
How is JWT used for authentication and authorization?
Mid
Discuss the security implications and trade-offs of storing JWTs on the client side, such as in HTTP-only cookies vs. local storage.
Mid
What is the difference between an access token, refresh token, and ID token in the context of OAuth 2.0 and OpenID Connect?
Mid
What are the standard claims in a JWT (iss, sub, aud, exp, iat, nbf, jti) and what is the purpose of each?
Mid
Is a JWT encrypted or encoded? Explain the difference and its security implications.
Mid
Explain the concept of token introspection and when it would be used.
Mid
Explain the concept of token revocation and why it's important.
Mid
How do you handle token expiration in JWT?
Mid
How can you refresh a JWT token?
Mid
What are the challenges of JWT revocation, and what strategies are used to mitigate them?
Senior
What is the difference between symmetric and asymmetric signing algorithms in JWT?
Senior
What are the security implications of using JWT?
Senior
What is the difference between opaque tokens and self-contained (e.g., JWT) tokens, and when would you choose each?
Senior
What is token binding, and how does it help prevent token theft and replay?
Senior
What is the difference between JWS and JWE, and when would you need an encrypted JWT?
Senior
How does a JWKS endpoint and public-key rotation work for validating signed tokens?
Senior
Oauth & Openid Connect
What is the main difference between OAuth 2.0 (for authorization) and OpenID Connect (for authentication)?
Junior
What is user consent in OAuth, and what role does the consent screen play?
Junior
Explain OAuth 2.0. What problem does it solve, and what are its core roles (resource owner, client, authorization server, resource server)?
Mid
Explain OpenID Connect (OIDC). How does it build on OAuth 2.0, and what additional functionality does it provide (ID Token, UserInfo Endpoint)?
Mid
What are OAuth scopes, and how do they limit the permissions granted to applications?
Mid
What is the purpose of the state parameter in the OAuth authorization code flow?
Mid
Why is OAuth 2.0 often misused for authentication, and what problems does that cause?
Mid
What is machine-to-machine authentication, and how does the client-credentials flow support it?
Mid
What is the purpose of the nonce in OpenID Connect?
Mid
What is discovery in OpenID Connect, and how does the well-known configuration endpoint help clients?
Mid
Describe the Authorization Code flow with PKCE in OAuth 2.0. Why is PKCE important, especially for public clients?
Senior
Explain other OAuth 2.0 grant types such as Client Credentials, Device Code, Implicit, and Resource Owner Password Credentials, and discuss their use cases and why some are deprecated or discouraged.
Senior
What is the difference between the front channel and back channel in OAuth flows, and why does it matter for security?
Senior
What are the key changes introduced in OAuth 2.1 compared to OAuth 2.0?
Senior
What is OAuth token exchange, and when would you use it?
Senior
Explain the difference between delegation and impersonation, and how the on-behalf-of flow works.
Senior
Federated Identity & Sso
Explain the concept of Single Sign-On (SSO) and how protocols like SAML or OIDC facilitate it.
Mid
What's the difference between JWT, OAuth, and SAML?
Mid
Explain the conceptual flow of Kerberos authentication. What are its main components (KDC, AS, TGS)?
Mid
What is LDAP and how is it used as an identity store, particularly with Active Directory?
Mid
Explain how SAML assertions work and the roles of the Identity Provider and Service Provider.
Mid
What is the difference between a centralized identity provider and per-application authentication? What are the trade-offs?
Mid
What is social login, and what are the risks of relying on a third-party identity provider?
Mid
Compare SAML and OpenID Connect. Discuss their differences in data format, use cases, and when you would choose one over the other.
Senior
What is the difference between SP-initiated and IdP-initiated SSO?
Senior
What is federated identity, and how is trust established between organizations?
Senior
Multi Factor & Passwordless
Can you explain how OTP (One-Time Password) is used for verification in an authentication flow?
Junior
Explain Multi-Factor Authentication (MFA). What are its common types such as TOTP, push-based, and biometrics, and their trade-offs?
Mid
What are Passkeys / WebAuthn / FIDO2, and what problems do they solve compared to traditional password-based authentication?
Mid
What is MFA fatigue/bombing, and how can it be mitigated?
Mid
What is the difference between TOTP and HOTP one-time passwords?
Mid
Why is SMS-based OTP considered a weaker second factor, and what attacks target it?
Mid
How do magic-link and one-time-code passwordless flows work, and what are their trade-offs?
Mid
How does biometric authentication work as a factor, and what do false-accept and false-reject rates mean?
Mid
What is the role of recovery codes in MFA, and how should they be stored and handled?
Mid
What is step-up (adaptive) authentication, and when would you require it?
Senior
What does 'phishing-resistant authentication' mean, and why is WebAuthn considered phishing-resistant?
Senior
Session Management
Compare and contrast session-based authentication and token-based authentication such as JWT. Discuss their statefulness, scalability, and security trade-offs.
Mid
Explain session fixation and session hijacking attacks. What are common mitigations?
Mid
How can CSRF attacks impact authentication (against session cookies), and what are the primary defenses (SameSite cookies, anti-CSRF tokens)?
Mid
What are the Secure, HttpOnly, and SameSite attributes for cookies, and how do they enhance security for session management?
Mid
What is the difference between idle (inactivity) timeout and absolute session timeout, and why use both?
Mid
How does server-side session invalidation on logout work, and why is stateless logout harder?
Mid
Api & Service Authentication
Describe the use cases and limitations of API keys for authentication.
Junior
What is authentication in API design?
Junior
What is the difference between a 401 Unauthorized and a 403 Forbidden response?
Junior
Explain the API Gateway authentication pattern and its benefits.
Mid
What is the role of authentication and authorization middleware, and why is their order important?
Mid
Can you describe the process of authentication and authorization in Web APIs?
Mid
Explain the HTTP authentication schemes — Basic, Digest, and Bearer — and how the Authorization header is used with each.
Mid
What is the purpose of the WWW-Authenticate header and the 401 challenge in HTTP authentication?
Mid
Discuss common patterns for service-to-service authentication in a microservices architecture, such as mTLS and signed service tokens.
Senior
How do you implement authorization checks with JWT claims, especially in a microservices architecture?
Senior
How does certificate-based (mutual TLS) authentication work as an identity mechanism?
Senior
Should authorization be enforced at the API gateway or inside each service? Discuss the trade-offs.
Senior
How is a token propagated across services in a microservices call chain, and what are the risks?
Senior
Zero Trust Architecture
What is Zero Trust Architecture? Explain its core principles, such as 'never trust, always verify' and continuous verification.
Mid
How does Zero Trust differ from traditional perimeter-based security?
Mid
How is identity important in Zero Trust Architecture?
Mid
Explain the role of micro-segmentation in a Zero Trust model.
Senior
Authorization Vulnerabilities
What is Broken Authentication and what are common vulnerabilities that lead to it?
Mid
What is Broken Access Control? Why is it considered one of the most critical OWASP vulnerabilities?
Mid
Explain horizontal vs. vertical privilege escalation.
Mid
What is broken object-level authorization (BOLA) or Insecure Direct Object References (IDOR), and how do you prevent them?
Senior
Authentication Attacks & Defenses
What is the difference between a brute-force attack and a dictionary attack, and what are common prevention methods for each?
Junior
What are replay attacks in the context of authentication, and how can they be prevented (jti claim, short-lived tokens)?
Mid
What is token theft (e.g., via XSS) and how can it be mitigated, especially when using JWTs?
Mid
What is credential stuffing, and how does it differ from password spraying? How do you defend against each?
Mid
What defenses against brute-force login attempts do you know — rate limiting, account lockout, CAPTCHA — and their trade-offs?
Mid
What is account (username) enumeration, and how do timing and error-message differences leak it?
Mid
How do you design a secure password-reset and account-recovery flow?
Senior
What is an open-redirect vulnerability via the redirect_uri in OAuth, and how do you prevent it?
Senior
Jwt Attacks
How does a weak signing secret enable a JWT attack, and how do you protect against it?
Mid
Explain JWT-specific attacks such as 'alg:none' bypass and algorithm confusion (RS256 to HS256 downgrade). How are they mitigated?