Basic Cryptography Lecture Notes

This set of flashcards covers the fundamental concepts and terminology related to basic cryptography, including security models, encryption methods, and key concepts in cryptographic practices.

CIA Model

The classic security model which stands for confidentiality, integrity, and availability.

Confidentiality

Information is only disclosed to those authorized to know it.

Integrity

Only authorized parties can modify information in allowed ways.

Availability

Authorized individuals are not prevented from accessing information.

Cryptography

The practice of securing information and communications through the use of codes.

Encryption

The process of converting plain text into cipher text to protect information.

Decryption

The process of converting cipher text back into plain text.

Symmetric Key Cryptography

A type of cryptography where the same key is used for both encryption and decryption.

Asymmetric Key Cryptography

A type of cryptography that uses a public key for encryption and a private key for decryption.

Cryptographic Hash Function

A function that takes an arbitrary length message and produces a fixed size hash value.

One-way function

A function that is easy to compute in one direction but hard to reverse.

Weak Collision Resistance

It should be hard to find a different input that hashes to the same output.

Strong Collision Resistance

It should be hard to find any two different inputs that hash to the same output.

AES

Advanced Encryption Standard; a widely used symmetric encryption algorithm.

RSA

Rivest-Shamir-Adleman; a widely used asymmetric encryption algorithm.

Digital Signature

A cryptographic scheme that joins hashing and public key cryptography to verify a message's authenticity.

Digital Certificate

A document that uses a digital signature to verify the ownership of a public key.

Chain of Trust

A trust model that relies on the security of public keys and the verification process in certificate authorities.

SSH Authentication

A secure method of logging into a remote server using public key cryptography.

MD5

A cryptographic hash function that is no longer considered secure due to vulnerabilities.

SHA-256

A cryptographic hash function that produces a 256-bit hash and is currently considered secure.