Encryption is a reversible process that transforms cleartext data into ciphertext to protect confidentiality. It uses cryptographic keys to both encrypt and decrypt data, ensuring that only authorized parties can access the original data.
Hashing, on the other hand, is a one-way function that converts data into a fixed-length hash value or checksum. Hashing is primarily used to verify data integrity by detecting changes, since any modification in the input will produce a different hash output. Unlike encryption, hashing cannot be reversed to obtain the original data.
While encryption can protect data both at rest and in transit, hashing does not protect data confidentiality but supports integrity verification. Public-key exchange is a cryptographic mechanism within asymmetric encryption but is unrelated to hashing key usage.
This distinction is thoroughly explained in the Cryptography chapter of the SY0-701 syllabus#6:Chapter
7 CompTIA Security+ Study Guide#.