Getting Started with Encryption

Introduction

Welcome to the world of encryption, a vital tool for protecting information in our increasingly digital world. Whether we're a budding tech enthusiast, a privacy-conscious individual, or just someone curious about how information is kept secure, understanding encryption is crucial. In this blog post, we'll break down the basics of encryption, explore its different types, and provide pointers for further exploration.

Defining Encryption and Decryption

Encryption is the process of converting information or data, often referred to as plain text, into a code, often referred to as ciphertext, making use of a set of characters called an encryption key. It's like sending a secret message that only the intended recipient knows how to decode it. In the digital realm, encryption secures data ranging from emails to financial transactions. 

Decryption is the opposite of encryption. It converts the ciphertext back into plaintext either using the same encryption key that was used for encryption or a key that is mathematically related to the one used for encryption. This cipher text can only be turned back into readable plain text by someone who has the correct decryption key, thus preventing unauthorized access.

Important Concepts in Encryption

• Plain Text: The original, readable information or data that needs to be encrypted.
• Cipher Text: The encrypted version of the plain text, which appears as seemingly random characters.
• Encryption Key: A string of characters used in the encryption/decryption process. Longer keys provide higher security. Based on the encryption key used in the encryption/decryption process, we can categorize encryption into symmetric encryption and asymmetric encryption. 
  • Symmetric encryption uses the same key for both encrypting and decrypting data. 
  • Asymmetric encryption, also known as public-key cryptography, uses two different but mathematically linked keys – a public key and a private key. Data encrypted with the public key can only be decrypted with the private key and vice versa.
• Encryption Algorithm: A set of mathematical rules that governs the process of converting plain text into cipher text and vice versa.
• Encryption Context: Based on the context in which encryption is applied, we can categorize encryption into Encryption at Rest and Encryption in Transit (or Encryption in Flight). 
  • Encryption at Rest refers to encrypting data that is stored on a physical device or in cloud storage. It's crucial for protecting stored data from unauthorized access, such as in cases of device theft or data breaches.
  • Encryption in Transit/Flight secures data while being transmitted over a network and helps prevent MITM (man in the middle) attacks. Techniques like HTTPS, which use TLS (Transport Layer Security), are examples of encryption in transit, safeguarding data during its journey across the internet.

In summary, in encryption, plain text is transformed into cipher text using an encryption algorithm and an encryption key. This cipher text can only be turned back into readable plain text by someone who has the correct decryption key. The process of encryption and decryption can happen on data at rest or in transit.

Getting Started with Symmetric Encryption

What is it?
Symmetric encryption is the oldest and most straightforward encryption technique. It uses the same key for both encrypting and decrypting data. Think of it like a lock and key; the same key that locks (encrypts) the information unlocks (decrypts) it.

Use Case:
While symmetric encryption is efficient for encrypting data on a single device, it's also widely used in network communications after a secure connection is established. 

Popular Algorithms:

• Advanced Encryption Standard (AES)
• Triple Data Encryption Standard (3DES)

Read more at secdops.com/blog/getting-started-with-symmetric-encryption.

Getting Started with Asymmetric Encryption

What is it?
Asymmetric encryption, also known as public-key cryptography, uses two different but mathematically linked keys – a public key and a private key. The public key, as the name suggests, is open to everyone, but the private key is kept secret. Data encrypted with the public key can only be decrypted with the private key and vice versa.

Use Case:
This type of encryption is widely used in sending information across the internet. For instance, when you visit a secure website (HTTPS), asymmetric encryption helps in establishing a secure connection. 

Popular Algorithms:

• RSA (Rivest–Shamir–Adleman)
• ECC (Elliptic Curve Cryptography)

Read more at secdops.com/blog/getting-started-with-asymmetric-encryption.

HTTPS Handshake: A Combination of Asymmetric and Symmetric Encryption

In practice, a combination of both symmetric and asymmetric encryption – known as hybrid encryption – is often used. It provides the speed of symmetric encryption with the security of asymmetric encryption. For example, in HTTPS connections, after the initial handshake which often uses asymmetric encryption to exchange keys, the actual data transfer typically switches to symmetric encryption using the exchanged key. 

• Asymmetric Encryption: Used in the initial phases of the handshake (e.g., encrypting the pre-master secret with the server's public key), providing a secure method for exchanging key information without prior shared secrets.
• Symmetric Encryption: Employed for encrypting the actual data transferred in the session for efficiency, as it's faster than asymmetric encryption once the shared secret (session key) is established.

Read more about HTTPS handshake at Decoding the HTTPS Handshake for Absolute Beginners.

Exploring Further

To deepen your understanding of encryption, you might want to explore:

• Key Distribution: The process of sharing encryption keys. In asymmetric encryption, this is simpler as the public key can be freely distributed.
• Digital Signature: A way to verify the authenticity of a digital message, using asymmetric encryption.
• Cryptographic Hash Functions: Used to secure passwords and create data fingerprints. They convert data into a fixed-size hash, which can't be reversed to find the original data.
• Cryptographic Protocols: Such as SSL/TLS for securing internet communications.
• Cryptanalysis: The study of methods for breaking cryptographic codes.
• Quantum Cryptography: An emerging field using quantum mechanics principles to develop theoretically unbreakable encryption.

Conclusion

Encryption is a dynamic and fascinating field, constantly evolving to meet new security challenges. By understanding its basics and applications, you're taking a vital step in safeguarding your digital information. Whether you dive into the complexities of cryptographic algorithms or simply use encryption tools to protect your data, you're contributing to a more secure digital world.

See also

Read about Envelope Encryption at secdops.com/blog/understanding-envelope-encryption.