Cybersecurity: Encryption, Hashing, and Network Security Principles

Encryption

process of converting an original message into a form that is unreadable to

unauthorized individuals − that is, to anyone without the tools to convert the encrypted

message back to its original format.

Decryption

process of converting the ciphertext message back into plaintext so that it can be

readily understood.

algorithm

programmatic steps used to convert an unencrypted message into an

encrypted sequence of bits that represents the message.

Substitution

process of replacing plaintext values with other values to form ciphertext.

Hash algorithms

mathematical functions that create a hash value, also known as a message digest, by

converting variable-length messages into a single fixed-length value.

Salting

process of providing a nonsecret, random piece of data to the hashing function when

the hash is first calculated.

rainbow table

describes a database of precomputed hashes from sequentially calculated

passwords

message authentication code (MAC)

describe a key-dependent, one-way hash function that allows only

specific recipients (symmetric key holders) to access the message digest.

Least privilege

principle by which members of the organization are allowed to access the minimal

amount of information for the minimal amount of time necessary to perform their required

duties.

smart card

plastic card with an embedded microchip that can store data about the owner

dictionary attack

throws every known word (sometimes in many languages) into the authentication system until something matches what's stored on the system.

brute-force attack

tries every possible character, number, and symbol combination to guess the

password.

ward dialer

automatic phone-dialing program that dials every phone number in a configured

range (e.g., from 555-1000 to 555-2000) and checks to see if a person, answering machine, or modem answers.

intranet

internal network restricted to employees within the organization, also using Internet technologies.

End points

hardware devices or software modules that perform encryption to secure data,

perform authentication to make sure the host requesting the data is an approved user of

the VPN, and perform encapsulation to protect the integrity of the information being sent

tunnel

channel or pathway over a packet network used by the VPN; it runs through the

Internet from one endpoint to another.

intrusion

occurs when an attacker attempts to gain entry or disrupt the normal operations of an

information system, almost always with the intent to do harm

Incident response

encompasses the actions an organization takes when an intrusion is detected

Tuning

process of adjusting an IDPS to maximize its efficiency in detecting true positives while minimizing both false positives and false negatives

application protocol verification

higher-order protocols (HTTP, FTP, Telnet) are examined for unexpected packet

behavior or improper use

Honeypots

decoy systems designed to lure potential attackers away from critical systems

honeynet

When a collection of honeypots connects several honeypot systems on a subnet

Enticement

process of attracting attention to a system by placing tantalizing information

in key locations

Entrapment

act of luring an individual into committing a crime to get a conviction

SSL

cryptographic protocol designed to provide secure communication over a computer network

TSL

successor to SSL and is a more secure and modern cryptographic protocol

IPsec

designed to secure IP communications by authenticating and encrypting each IP packet in a data stream

Symmetric Encryption

cryptographic technique where one secret key is shared between parties to securely encrypt and decrypt messages

Hashing

process of running input data (of any size) through a hash function to produce a fixed-size output called a hash value

CIA

core goals of information security that guide policies, controls, and risk management

Confidentiality

Ensuring information is not disclosed to unauthorized individuals, systems, or processes

Integrity

Ensuring information is accurate, complete, and unchanged except by authorized actions

Availability

Ensuring authorized users and systems can access information and services when needed.