thinQmaster Virtual testing partner Adaptive practice exams that find your weak spots and drill them. Every answer explained. From $69
Enroll

thinQmaster

Find your exam

Five questions free, before you decide.

Step 1 · choose a vendor

In one of our camps? Your practice exams come with the tuition — they are on your study page already.

Security Fundamentals & Crypto · Foundational

Encryption

Converting plaintext into ciphertext using an algorithm and key so only authorized parties can read it.

Definition

Encryption protects confidentiality by making data unreadable without the correct key. It may be symmetric (same key to encrypt and decrypt) or asymmetric (public and private key pair). Decryption reverses the process with the appropriate key.

Example

openssl enc -aes-256-cbc -pbkdf2 -in report.pdf -out report.pdf.enc encrypts a file with a password-derived key.

Exam tip

Encryption is reversible with a key; hashing is one-way. Exams often test this difference.

Don't confuse it with

Related terms