Message digests use which of the following?

DES and RC4 are symmetric encryption algorithms used for data confidentiality, not for producing message digests.

IDEA and RC4 are both symmetric block and stream ciphers respectively, and neither is a hashing or digest algorithm.

SSL is a transport security protocol, not a hashing algorithm, and pairing it with MD4 does not correctly describe message digest functions.

SHA-1 (Secure Hash Algorithm 1) and MD5 (Message Digest 5) are both cryptographic hash functions designed specifically to produce fixed-length message digests from variable-length input. They are widely used for verifying data integrity, digital signatures, and certificate fingerprints. These algorithms are defined as one-way functions, making it computationally infeasible to reverse the digest to the original input.