Which algorithm does the IOS 'enable secret' option use to protect the device password?

The enable secret command in Cisco IOS uses the MD5 (Message Digest 5) hashing algorithm to encrypt the password. MD5 is a one-way cryptographic hash function, meaning the original password cannot be easily derived from the hash. This provides a more secure way to store the enable password compared to the enable password command, which stores the password in plain text or uses a weak, easily reversible encryption (Type 7). PAP (Password Authentication Protocol) and CHAP (Challenge Handshake Authentication Protocol) are authentication protocols, not hashing algorithms for local password storage. AES (Advanced Encryption Standard) is a symmetric-key encryption algorithm used for data encryption, not typically for hashing local passwords in this context.