What is Encryption?

Encryption converts readable data (plaintext) into a scrambled and unreadable format (ciphertext) using an algorithm and a key. The primary purpose of encryption is to ensure the confidentiality and security of information during transmission or storage.

Types of encryption

There are three primary types of encryption: 

  • Symmetric Encryption: Symmetric encryption, also known as secret-key encryption, involves using a single key for encryption and decryption. Symmetric encryption is generally faster and more efficient than asymmetric encryption, but it requires a secure communication channel to share the encryption key between the sender and the recipient. Examples of symmetric encryption algorithms include Advanced Encryption Standard (AES), Data Encryption Standard (DES), and Triple DES (3DES).
  • Asymmetric Encryption (Public Key Encryption): Asymmetric encryption uses a pair of keys: a public key for encryption and a private key for decryption. The public key is openly shared, meaning anyone can encrypt the data, but only the holder of the corresponding private key can decrypt it. Asymmetric encryption is slower than symmetric encryption but eliminates the need for secure key exchange. Organizations use it for secure data transmission, digital signatures, and key exchange protocols. Examples of asymmetric encryption algorithms include RSA, Diffie-Hellman, and Elliptic Curve Cryptography (ECC).
  • Hash Functions: While not encryption in the traditional sense, hash functions are cryptographic tools used for data integrity verification and password storage. Hash functions generate a fixed-size output (hash value) from an input (message), and even a tiny change in the input leads to a wildly different hash value. Hash functions then verify data integrity, generate digital signatures, and securely store passwords (using techniques like salting).

It’s important to note that most encryption systems utilize two or more types in tandem. For instance, in secure communication, the user might use asymmetric encryption to establish a secure channel. From there, symmetric encryption is used for the actual data transmission, as it’s faster for larger amounts of data.

Components of encryption

The encryption process involves four critical components:

  • Plaintext: This is the original, readable data the handler wants to protect. It could be a message, a file, or any information.
  • Encryption Algorithm: An encryption algorithm is a set of mathematical rules and operations determining how the plaintext transforms into ciphertext. Modern encryption algorithms are complex and challenging to reverse engineer without the appropriate decryption key.
  • Encryption Key: The encryption key guides the encryption algorithm in converting plaintext into ciphertext. The key is essentially a parameter that determines the specific transformation process. The choice of key significantly impacts the security of the encrypted data.
  • Ciphertext: This results from applying the encryption algorithm to the plaintext using the encryption key. Ciphertext appears as random and unreadable data, making it difficult for unauthorized individuals to understand without the decryption key.

Stages of encryption

The basic steps of encryption are as follows:

  • Key Generation: The first step is to generate the encryption key(s) based on the chosen encryption algorithm. A single secret key is used for encryption and decryption in symmetric encryption. In asymmetric encryption, a key pair consisting of a public and private key is generated.
  • Encryption: The encryption process takes the plaintext and the encryption key as input and applies the encryption algorithm to produce the ciphertext. The algorithm performs a series of mathematical operations, transforming the plaintext into a format that appears random and meaningless.
  • Ciphertext Transmission: The ciphertext can now be safely transmitted or stored without the risk of unauthorized access. Even if an attacker intercepts the ciphertext, they won’t be able to understand it without the decryption key.
  • Decryption: The recipient uses the corresponding decryption key to retrieve the original plaintext from the ciphertext. In symmetric encryption, the same key is used for encryption and decryption. In asymmetric encryption, the recipient uses their private key to decrypt data encrypted with their public key.
  • Original Plaintext Recovery: The recipient successfully converts the ciphertext back into the original plaintext by applying the decryption algorithm and the decryption key. The original data is now accessible and readable.

The future of encryption

The future of encryption is an uncertain one. Quantum computing has the potential to render traditional encryption methods obsolete. Fortunately, computer scientists are developing post-quantum cryptography in an attempt to counter this threat. However, as data breach attack methods grow increasingly sophisticated, encryption will remain crucial for safeguarding digital communication, privacy, and sensitive information. End-to-end encryption may become the norm across platforms, enhancing individual privacy. Encryption’s effectiveness could also face regulatory and legal debates regarding government access to encrypted data for security reasons. Striking a balance between security, privacy, and law enforcement will shape encryption in our increasingly interconnected and data-driven world.

For more essential cybersecurity definitions, check out our other blogs below: 

21 Essential Cybersecurity Terms You Should Know

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