What is Encryption and Decryption?

You can watch this video on Encryption and Decryption in Cryptography:

Before we can start talking about encryption and decryption, let us have a little discussion about cryptography.

Humans have been using cryptography for as long as they have wanted to keep messages secret. Cryptography is the process of protecting and securing data. It helps prevent unidentified entities from accessing sensitive or confidential data. Governments have been using cryptography for military purposes for a long time. The ancient Greeks and Romans used to send secret messages using ciphers that were only decipherable by specific keys. The Caesar Cipher is an example of early cryptography. Cryptography has two important functionalities—encryption and decryption. Let us discuss them in more detail.

What is Encryption?

Encryption is the process in which messages are changed into an unidentifiable form. The encrypted message is then sent over the network. The sender needs an encryption algorithm along with a key that helps change the message into ciphertext. Encryption is also commonly referred to as enciphering.

The data that is encrypted is called plaintext. The encrypted, unrecognizable data is called ciphertext. The cryptographic algorithm that helps transform the plaintext into ciphertext, using a key, is known as the encryption algorithm.

Get our Cyber Security Course in collaboration with IIT Guwahati to master cyber security.

What is Decryption?

Decryption is the reverse process of encryption. Decryption converts the ciphertext back to plaintext. The receiver has to use a decryption algorithm and a key to decipher the ciphertext. Deciphering is another word for decryption.

The decryption algorithm is the reverse process of the encryption algorithm. The decryption algorithm uses the ciphertext and the key to change ciphertext to plaintext.

Encryption and Decryption Keys

Keys are the string of bits created randomly for the specific purpose of encrypting and decrypting data. The keys for encryption and decryption can be the same or different, depending on the encryption method used. All keys are made via algorithms to make sure they are difficult to guess. They are usually generated using random number generators.

Let us take a look at some different types of keys:

• Symmetric Key: Symmetric key encryptions use the same key for both encryption and decryption.
• Asymmetric Key: Asymmetric key encryptions use two different sets of keys for encryption and decryption. The public key can be accessed by anyone, while the secret key is only with the receiver.
• Public Key: Public key cryptography is based on two pairs of keys.
• Private Key: A private key can be a part of either the public or private asymmetric key pair. It is used in symmetric encryption as well.
• Pre-shared key: A pre-shared key is shared securely between parties before it is used.

Difference Between Encryption and Decryption

Let us take a look at the major differences between encryption and decryption:

Check our Cyber Security interview question and answers if you are preparing for your next cyber security job interview!

What are Some Common Encryption and Decryption Algorithms?

There are many encryption and decryption algorithms available today. Let us take a look at some of the most commonly used encryption and decryption algorithms:

AES:

The Advanced Encryption Standard (AES) is used by the US government and other organizations because of how trustworthy it is. It is capable of carrying out encryption of up to 256-bit keys. AES is considered invulnerable to attacks except for brute-force attacks.

Triple DES:

Triple DES was released as a response when hackers figured out how to crack the original Data Encryption Standard (DES) algorithm. Triple DES is based on symmetric encryption, which is now slowly phasing out. In Triple DES, the DES algorithm is applied three times to data blocks. It is commonly used to encrypt ATM PINs and UNIX passwords.

RSA:

RSA is a type of public-key encryption algorithm. It is considered the standard encryption algorithm for data on the internet. RSA works by creating a lot of useless data that ends up confusing hackers and wasting their time.

Blowfish:

Blowfish was designed to replace DES. Blowfish is a symmetric encryption algorithm that breaks messages into blocks of 64-bits. These blocks are then encrypted individually. Blowfish is known for its flexibility and speed. It is free and unbreakable. It is also widely used on e-commerce platforms.

Twofish:

Twofish was released as a successor to Blowfish. Twofish is a symmetric encryption algorithm that works with 128-bits of data blocks. It encrypts data in rounds, not depending on the size of the key. It works for both hardware and software.

Why Do We Need Encryption and Decryption?

Even though encryption and decryption cannot foolproof your security, you can still use them to protect your identity and privacy.  If you are ever being watched, you can have data privacy by using well-implemented encryption and decryption systems.

Encryption and decryption systems work best when they are automated. They should not be a feature that you turn on only when you are doing something that you feel is worth protecting; they should be enabled by default.

Want to Decrypt Encrypted messages legally for a better cause? Then enroll in CEH Training.

Encryption and Decryption Tools

Let us take a look at some of the best free encryption and decryption software tools available:

LastPass:

LastPass is one of the most popular password managers available. It has limited features in the free version, but it protects your passwords and personal data well. With this tool, you do not have to make a note or remember all your passwords. It has a good UI, which makes it easy to use. It also comes with Firefox and Chrome extensions.

BitLocker:

BitLocker is a widely preferred tool for protecting local data. It can encrypt and decrypt a specific disk partition or the entire hard disk depending on your preferences. It uses the AES algorithm to encrypt and decrypt the data on the drives.

VeraCrypt:

VeraCrypt also uses the AES algorithm to encrypt and decrypt volumes within volumes. It is available for Windows, OS X, and Linux operating systems. It is an open-source program, so researchers and developers can use the source code as well.

FileVault 2:

FileVault 2 is a free encryption and decryption tool that can help encrypt and decrypt data on macOS and Mac hardware. FileVault 2 uses the XTS-AES-128 encryption algorithm with a 256-bit key.

DiskCryptor:

DiskCryptor is an open-source, free encryption and decryption software that can help secure your external and internal drives, USB flash drives, ISO images, or other storage devices. It uses multiple encryption and decryption algorithms such as AES, Blowfish, etc.

Applications of Encryption and Decryption

Let us take a look at some of the everyday applications of encryption and decryption:

Digital Signature or Authentication

Authentication, or the process of proving and verifying information, requires the process of encrypting and decrypting important information. A digital signature is based on the document and the signer’s key, and it hence, requires to be encrypted and decrypted to maintain safety.

Timestamping

Timestamping is based on the process of encryption and decryption. It helps verify that an electronic document or communication was delivered on time.

Electronic Money

With electronic money, transactions are carried out electronically by the transfer of funds between parties. These transactions are encrypted and decrypted to save sensitive user data.

Encryption and Decryption in Email

Emails are encrypted so that nobody outside of the email conversation is able to read the contents of the emails. They can be decrypted using a private key that only the receiver can access.

Check out this Cybersecurity Tutorial to learn Cybersecurity Essentials!

Conclusion

Encryption and decryption are important to keep data secure and private. There are various tools available online that can help you encrypt and decrypt your data. These tools employ different encryption and decryption algorithms, and you can choose one according to your needs.