Our means of communication have changed significantly over the past two decades. Today we have many channels of communication apart from traditional telephones - emails, social media platforms, internet voice calling, video calling, mobile-based messaging apps, and more. All these new channels are basically supported by the internet. This means whatever you communicate with other people is via transmission of data online. Now, you must already be aware that data present online can be compromised by malicious hackers. So obviously, when using internet-based channels, you must be concerned about the security of data. You would expect that your message would reach the right person and doesn't come under the radar of everyone else, including hackers. This is where cryptography comes in.

Basically, cryptography refers to secure information and communication techniques that ensure only the sender and recipient of the message are able to read it, preventing any third party from being able to do so. There are certain mathematical concepts and algorithms (sets of rule-based calculations) that help transform such private messages into information that is hard to decode. Cryptography has gained much popularity as companies continue to focus on Data security. Many information security job roles require the knowledge of cryptography as a must-have skill. This is the reason people aspiring to start a career in IT security often take Cryptocurrency free courses to learn the subject from scratch.

This article gives you a complete overview of cryptography and how its knowledge can help enhance your career prospects.

Cryptography Explained
Cryptography is used in a number of applications these days, like digital currency, digital signatures, transactions in e-commerce applications, encrypting military communication channels, credit card transactions, secure web browsing, authentication, and computer passwords. When we talk about modern cryptography, it aims to maintain confidentiality, meaning the message can’t be deciphered by anyone other than the sender and receiver. Whatever the mode of message transmission, the information can’t be modified at any stage. Moreover, both the sender and recipient should be able to verify each other’s identities and the information’s source and destination. In other words, cryptography works on four principles - confidentiality, authentication, integrity, and non-repudiation.

Here are some of the common terms you should be aware of if you are a beginner in cryptography.

Plaintext - It is the message that needs to be sent from sender to receiver. It can be in the form of text, binary content, or even image.

Encryption - It is the process used for converting plaintext into an unreadable format. Generally, a secret key is used by cryptographers to cipher the given message. At the receiving end, this secret key is used to decode the message.

Cipher - A cipher usually refers to the algorithm used for encrypting and decrypting plaintext. When a cipher is applied, a set of clearly defined steps are followed, and the plaintext gets converted to ciphertext. These algorithms can be quite simple or even may be complex.

Secret key - A secret key is nothing but a group of digits used to transform plaintext into ciphertext and vice versa. According to the National Institute of Standards and Technology (NIST), the recommended key length for Symmetric algorithms is 128 bits, for Asymmetric algorithms is 2048 bits, and that for Hash functions is 256 bits. All these three types of algorithms are discussed in the next section.

Decryption - It is the procedure wherein the secret key is used to transform the ciphertext back into plaintext.

Cryptography Types
Let us now take a look at the types of cryptography.

Symmetric-key cryptography
In this type of encryption technique, the message is encrypted and decrypted using the same shared key by both the sender and the recipient. This technique is also known as single-key encryption, and one of its popular examples is Advanced Encryption Standards (AES).

Asymmetric-key cryptography
As opposed to symmetric key cryptography, asymmetric key encryption involves different keys to code and decode and message. The key associated with the sender is a public key (for encrypting), and that for the receiver is a private key (for decrypting). This technique is also known as public key cryptography. A popular example of this type of cryptography is the RSA algorithm or Rivest, Shamir, and Adelman.

Hash functions
Unlike the above two types, hash functions do not involve any key. These are one-way operations used to obstruct access to the original plaintext in order to safeguard the message. Since the text is converted into a fixed-length string by the hash function, the only way to check the message is to test every conceivable input up until the stored hash matches.

Wrap Up
The use of cryptography for regular data transit has become the norm. When you are using popular messaging apps like Whatsapp and Facebook messenger, your private conversations are encrypted by these apps both during transit and at rest. Apart from these social platforms, customer data is shared across various online channels, and this information could be damaging if exposed to malicious hackers. So, it is high time that organizations use cryptography to guarantee that only intended users can access it. If you want to learn more about free online courses on this interesting subject, you can enroll in a reputed cryptography training course.