Security Filtering—Encryption and Remote Access

Vocabulary flashcards covering key encryption concepts and terms from the lecture.

Encryption

The process of obscuring information to make it unreadable without special knowledge, key files, or passwords.

Key

A string of numbers or letters stored in a file that, when processed through a cryptographic algorithm, can encode or decode data.

Symmetric-Key Encryption

Both the sender and receiver have the same key and use it to encrypt and decrypt all messages.

Asymmetric-Key Encryption

The sender and receiver each have their own pair of keys—one public key and one private key.

Data Encryption Standard (DES)

A symmetric-key algorithm with 56-bit keys, standardized by the U.S. government in 1977.

Triple Data Encryption Standard (3DES)

A symmetric-key algorithm that applies DES three times; can use one, two, or three keys (three-key 168-bit). Slower and being phased out in favor of AES.

Advanced Encryption Standard (AES)

A widely used symmetric-key standard with 128, 192, or 256-bit keys; established by NIST; 128-bit security for most needs, with higher keys for top-secret data.

Public-Key Encryption

An asymmetric method that uses a public key to encrypt and a private key to decrypt; may involve digital certificates for verification.

Diffie-Hellman Algorithm

A public-key method for securely exchanging cryptographic keys over a public channel.

RSA Encryption

A widely used public-key cryptosystem for secure data transmission, named after Rivest, Shamir, and Adleman.

Pretty Good Privacy (PGP)

An early public-key encryption program for email that uses a session key encrypted with the recipient’s public key; also known for cryptographic privacy and authentication.

Session Key

A temporary symmetric key used to encrypt a data session; it is itself encrypted with the recipient’s public key for secure delivery.

Digital Certificate (Digital ID)

A credential that verifies the identity of the sender or recipient in public-key cryptography.