What is Cryptography? (Definition, Process, and Types)

The study of secure communications techniques that enable only the sender and the intended recipient of messages to read its contents is known as cryptography. The word "kryptos" comes from the Greek word "kryptos," which means "hidden." It is closely linked to encryption, which is the process of scrambling plaintext into ciphertext and then back again when it's received.

In addition, cryptography includes techniques such as microdots and merging to obfuscate information in photographs. Ancient Egyptians were known to apply similar techniques in complicated hieroglyphics, and one of the first modern cyphers is ascribed to Roman Emperor Julius Caesar.

Encryption and Decryption

At its most basic level, cryptography entails two steps: Encryption and Decryption. To encrypt the plaintext and convert it to ciphertext, the encryption process employs a cipher. Decryption, on the other hand, uses the same cipher to convert the ciphertext to plaintext.

Encrypting and decrypting email and other plain-text messages is the most common use of cryptography when transmitting electronic data. The symmetric or "secret key" approach is the most basic way.

Data is encrypted using the secret key, and the encoded message and secret key are then delivered to the receiver for decoding. What is the issue then? A third party is all they need to decode and read the communication if it is intercepted. Cryptologists invented the asymmetric or "public key" scheme to overcome this problem. Every user has two keys in this case: one public and one private. Senders encrypt the message and transmit it along after requesting the recipient's public key.

How Does Cryptography Work? An Example

Here's an illustration of how cryptography works.

  • Assume you wanted to encrypt a basic message like "Hello." So "Hello" is our plaintext (message).

  • We may now encrypt the message using "Caesar's Cipher" (also known as a shift cipher), which is one of the basic types of encryption.

  • We just move each letter a predetermined number of spaces up or down the alphabet with this cypher.

  • That is to say, A = D, B = E, C = F, D = G, E = H, F = I, and so forth.

  • Our plaintext "Hello" becomes the ciphertext "Khoor" when we use this cypher.

  • "Khoor" does not resemble "Hello" to the untrained eye. However, even the most inexperienced cryptographer could easily decipher the message and reveal its contents if they knew Caesar's encryption.

Types of Cryptography

Depending on the process they follow to encrypt and decrypt the data, cryptography can be categorized into different types such as Hashing, Symmetric Cryptography, Asymmetric Cryptography, and Key Exchange Algorithms.


Hashing is a sort of encryption in which a message is converted into an unreadable string of text for the purpose of confirming its contents rather than hiding it.

When the publisher of the files or software provides them for download, this sort of encryption is most typically employed to safeguard the transmission of software and huge files. The reason for this is that while calculating the hash is simple, finding a starting input that is a precise match for the required result is quite difficult.

Symmetric Cryptography

Symmetric Cryptography is perhaps the most classic kind of cryptography, and it's also the one you're most familiar with. This method of cryptography encrypts a message using a single key and then decrypts it after it has been received at the other end.

Asymmetric Cryptography

In contrast to symmetric cryptography which employs a single key for encryption and decryption, asymmetric cryptography uses two distinct keys for encryption and decryption.

The first key is a public key that is used to encrypt messages, while the second key is used to decode them. This method is that it can only decipher encrypted messages received from a public key.

Key Exchange Algorithms

This sort of cryptography isn't especially relevant to anyone outside of the cyber-security field. To safely exchange encryption keys with an unknown person, a key exchange algorithm such as Diffie-Hellman is utilized.

Updated on: 14-Apr-2022

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