Which of the following is a key establishment algorithm listed as supported by Fortezza cards?

• A. RSA
• B. Diffie-Hellman
• C. Fortezza-Kea
• D. AES

Answer: (C)

Key establishment is about deriving a shared secret that both parties can use to protect their communication. Fortezza cards are legacy DoD crypto tokens that implement a specific key establishment protocol named Fortezza-Kea to derive such a session key when establishing a secure channel. Among the options, Fortezza-Kea is the one that explicitly represents a key establishment algorithm used by Fortezza cards. The others serve different roles: RSA is a public-key algorithm used for encryption and signatures, Diffie-Hellman is a general key-exchange method, and AES is a symmetric encryption algorithm. Since the question asks for the key establishment algorithm listed as supported by Fortezza cards, Fortezza-Kea is the best fit.