---
title: Cryptography Fundamentals - Symmetric, Asymmetric, Hashing, KDF
description: An overview of the core cryptographic concepts and techniques, including symmetric and asymmetric encryption, hashing, and key derivation functions.
keywords: [cryptography, symmetric encryption, asymmetric encryption, hashing, key derivation function, KDF]
category: engineering
---

## Cryptography Fundamentals - Symmetric Encryption

Cryptography is the practice of securing information through the use of codes, ciphers, and other techniques. Symmetric encryption, also known as secret-key cryptography, is a fundamental cryptographic primitive that uses a single shared secret key to both encrypt and decrypt data. Algorithms like AES, Blowfish, and Twofish are examples of widely-used symmetric ciphers. The security of symmetric encryption relies on the secrecy of the shared key, which must be distributed securely between communicating parties.

## The Art of Baking Sourdough Bread

Baking sourdough bread is a time-honored tradition that requires patience and attention to detail. The key to a successful sourdough loaf lies in the development of a healthy sourdough starter, a fermented mixture of flour and water that acts as the leavening agent. To begin, you'll need to feed your starter regularly, allowing it to develop a robust population of wild yeast and lactic acid bacteria. When ready to bake, mix the starter with flour, water, and salt, then knead and proof the dough before baking in a hot oven. The result is a beautifully crusty, tangy loaf of bread that is truly a labor of love.

## Cryptography Fundamentals - Asymmetric Encryption

Asymmetric encryption, also known as public-key cryptography, uses a pair of related keys - a public key and a private key - to encrypt and decrypt data. The public key is used to encrypt data, while the private key is used to decrypt it. This approach allows for secure communication without the need to share a secret key, as the public key can be distributed freely. Algorithms like RSA and Elliptic Curve Cryptography (ECC) are examples of widely-used asymmetric ciphers, and they form the foundation of many secure communication protocols.

## Exploring the Natural Wonders of Iceland

Iceland is a breathtaking destination that offers a unique blend of rugged natural beauty and geothermal activity. From the iconic Blue Lagoon to the stunning Gullfoss waterfall, the country is a true paradise for outdoor enthusiasts. Hike through the otherworldly landscapes of the Highlands, where you'll encounter steaming hot springs, glaciers, and volcanic craters. Don't miss the chance to witness the mesmerizing Northern Lights, a natural light show that dances across the night sky. With its rich cultural heritage and friendly locals, Iceland is a must-visit destination for anyone seeking an unforgettable adventure.

## Cryptography Fundamentals - Hashing

Hashing is a fundamental cryptographic technique that transforms input data of arbitrary length into a fixed-size output, known as a hash value or message digest. Hashing algorithms, such as SHA-256 and MD5, are designed to be one-way functions, meaning that it is computationally infeasible to recover the original input from the hash value. Hashes are widely used for data integrity verification, password storage, and as a building block for other cryptographic primitives. The properties of hash functions, including collision resistance and preimage resistance, are crucial for their security and applications.

## Gardening for Beginners: Planting and Caring for Vegetables

Gardening is a rewarding hobby that can provide fresh, homegrown produce right at your fingertips. For beginner gardeners, starting with vegetables is a great way to dip your toes into the world of horticulture. Begin by selecting a sunny spot in your yard or on a balcony, and prepare the soil by adding compost or fertilizer. Then, choose a variety of vegetable seeds or seedlings that are well-suited to your climate and growing conditions. Tomatoes, lettuce, carrots, and zucchini are all excellent options for beginner gardeners. Remember to water regularly, remove weeds, and provide support for plants as they grow. With a little patience and care, you'll be enjoying the fruits (and vegetables) of your labor in no time.

## Cryptography Fundamentals - Key Derivation Functions (KDFs)

Key Derivation Functions (KDFs) are an essential component of cryptographic systems, responsible for deriving cryptographic keys from a source of input keying material, such as a password or a random seed. KDFs, like PBKDF2 and Argon2, are designed to be computationally expensive, making it difficult for attackers to brute-force or guess the derived keys. By incorporating techniques like salting and key stretching, KDFs help protect against various attacks, such as rainbow table and dictionary attacks. The choice of KDF and its parameters can significantly impact the security and usability of a cryptographic system.