An Overview of Cryptography and Steganography

Introduction

After the Data Security course at Haaga-Helia, I got more interested in diving deeper into the Cybersecurity world. This post is going to give you an overview of Network Security, what are the purposes of Cryptography and Steganography in Network Security and their types in Information Security.

Network Security

Network Security is a subset of Cybersecurity that strategically protects the data, applications, devices and systems, in short, the underlying network infrastructure that are connected to the network for them to work in a secure manner.

Network Security is important because we relies heavily on the internet and the network daily. Therefore, the need to sustain confidentiality and integrity of the data and guard it against unauthorized access has been rising.

There are many types of Network Security such as:

• Firewalls
• VPN
• Network segmentation
• Cloud security
• Intrusion detection and prevention
• Data loss prevention
• Email security
• Web security
• Wireless security

And the list goes on

Cryptography

Why Do We Need Cryptography?

Cryptography is the art and science of keeping messages secure. It is a technique to secure important information and communication by converting plain text into unintelligible text and vice-versa.

Data being breached or stolen by hackers is pretty familiar to us nowadays. Hackers could steal data from us through many methods such as sending phishing emails, sql injections, key logging, DoS/DDoS attacks etc. Cryptography could protect our data even when the data is breached or stolen because encrypted data can’t be decoded if hackers don’t have the encryption keys. Due to this nature of Cryptography, it could be also used for authentication.

Types of Cryptography

There are 3 most common Cryptography types:

1. Symmetric Key Cryptography (Secret Key Cryptography)
2. Asymmetric Key Cryptography (Public Key Cryptography)
3. Hash Functions

Symmetric Key Cryptography uses a common shared key for both encryption and decryption processes.

Asymmetric Key Cryptography uses 2 different keys - private key and public key - to encrypt and decrypt the information. Public key is used to encrypt and private key used to decrypt.

Hash Functions are non-reversible mathematical functions / algorithms that take in the data and produce fixed-size outputs called hash value

Steganography

What Is Steganography?

Steganography simply is the art of hiding data in plain sight. Steganography is the combination of 2 Greek words: steganos means “covered” or “hidden” and graph means “to write” –> hidden writing.

The main idea behind Steganography is to prevent suspicion about the existence of the information.

Forms of Steganography

Examples of Steganography

• Writing with invisble ink
• Embedding text in a picture
• Backward masking a message in an audio file
• Concealing information in metadata
• Embedding secret message in green, blue or red channels of an RGB image

Cryptography vs Steganography

Conclusion

It has been really interesting to do the research on this topic. Network Security is a very broad topic and this post can only scratch its surface. Still, I think the information provided here is a very good start for anyone who’s interested. My next blog is going to be about data hiding techniques in Cryptography. Stay tune for the next post! 😉