Which of the following uses public key cryptography to encrypt the contents of files?

NTFS is a file system providing permissions, journaling, and access control, but it does not itself encrypt file contents using public key cryptography.

DFS (Distributed File System) is a technology for organizing shared folders across multiple servers and has no file encryption capability.

RFS is not a recognized Windows file system or standard encryption technology associated with public key cryptography.

EFS (Encrypting File System) uses asymmetric public key cryptography to protect file contents. Each file is encrypted with a symmetric File Encryption Key (FEK), which is then encrypted with the user's public key and stored with the file. Only the holder of the corresponding private key can decrypt the FEK and access the file data.