Security keys are physical devices used to provide strong cryptographic authentication, making them highly resistant to phishing attacks. They offer a seamless and highly secure authentication experience. By combining something you have (the key) with something you know (such as a password), they offer robust protection against unauthorized access. Tokens, on the other hand, are either physical devices or apps that generate temporary passcodes (OTPs) or allow users to approve authentication requests. They are widely used in multi-factor authentication systems to ensure that the person attempting to access a system has something they physically possess, in addition to knowing their password. Both security keys and tokens significantly enhance the security of user accounts, making it much harder for attackers to gain unauthorized access.

 Types of Security Keys

1. USB Security Keys:
• These keys plug into a computer’s USB port and authenticate the user through cryptographic protocols (such as FIDO U2F or FIDO2).
• Example: YubiKey is a popular USB security key that supports multiple authentication protocols.
2. Bluetooth or NFC Security Keys:
• These keys use wireless communication (Bluetooth or Near Field Communication) to authenticate a user.
• They can be used for authentication on mobile devices or computers without needing a physical connection.
3. Biometric Security Keys:
• Some modern security keys may include biometric features (e.g., fingerprint scanning) to ensure only the authorized user can use the key.

Key Features of Security Keys

• FIDO2 Compliance: Many security keys are built around open standards such as FIDO2 and U2F (Universal 2nd Factor), allowing them to work across a variety of platforms and services securely.
• Phishing-Resistant: Security keys are resistant to phishing attacks because they use cryptographic authentication rather than relying on passwords that can be stolen.
  • Cryptographic Information:Security keys contain cryptographic information that uniquely identifies the device and the user, ensuring secure authentication. 

Benefits:

• Enhanced Security:They significantly reduce the risk of unauthorized access due to stolen or guessed passwords. 
• Multi-Factor Authentication:They are a key component of MFA, adding a "something you have" factor to authentication, alongside "something you know" (password) and "something you are" (biometrics). 

Types of Tokens

1. Hardware Tokens:
• A physical device, often in the form of a small key fob or smart card, that generates a one-time password (OTP) for use in login processes.
• Example: RSA SecurID is a well-known example of a hardware token.
2. Software Tokens:
• A software-based token is an app or program that generates OTPs or is used to facilitate authentication.
• Example: Google Authenticator, Authy, and Microsoft Authenticator apps generate time-based one-time passwords (TOTP) for MFA.
3. Push Notification Tokens:
• Some tokens work by sending a push notification to a user's mobile device, where they simply approve or deny a login attempt (a form of MFA).
• Example: Duo Security uses push notifications as part of their authentication system.

Key Features of Tokens

• One-Time Passwords (OTP): Tokens generate unique, time-sensitive codes that expire after a short period or after use. This makes them difficult to reuse or intercept.
• Multi-Factor Authentication (MFA): Tokens are often used in conjunction with other forms of authentication (e.g., passwords) to improve security.
• Security: Tokens protect access by ensuring that the user has the physical device (hardware token) or access to an app (software token) in addition to knowing a password.

Comparison

Security keys and tokens are both tools used to enhance security by verifying the identity of a user and protecting access to sensitive systems or data. They are part of multi-factor authentication (MFA) strategies, adding an additional layer of security beyond just usernames and passwords.