What is data encryption (data encryption)?

Basic components of encryption

The encryption process is based on several key elements:

• Encryption algorithm: A mathematical procedure or set of rules used to convert plaintext into ciphertext and vice versa. Examples of popular algorithms include AES, RSA, Blowfish.
• Encryption key: A secret parameter (a string of bits) used by an algorithm to encrypt data. Without knowing the key, it is virtually impossible to decrypt the data (using strong algorithms).
• Decryption key: The key used by the algorithm to reverse the encryption process and recover the plaintext from the ciphertext.

Types of encryption

There are two main types of encryption that differ in the way keys are used:

• Symmetric encryption: Uses the same key for both encryption and decryption of data. It is fast and efficient, but requires a secure way to exchange a common key between the parties to the communication. Examples of symmetric algorithms: AES (Advanced Encryption Standard), DES, 3DES, Blowfish.
• Asymmetric encryption (public key cryptography): Uses a pair of keys: a public key and a private key. The public key can be freely shared and is used to encrypt data. Only the holder of the corresponding secret private key can decrypt the data. Asymmetric encryption is slower than symmetric, but solves the problem of secure key exchange. It is also used to create digital signatures. Examples of asymmetric algorithms: RSA, ECC (Elliptic Curve Cryptography).

Often both types of encryption are used together (hybrid encryption), e.g. the asymmetric key is used to securely replace the symmetric key, which is then used to encrypt the actual data.

Applications of data encryption

Encryption is used in many areas to protect the confidentiality of information:

• Encryption of data at rest (Data at Rest): Protects data stored on hard drives, databases, portable media (e.g. whole disk encryption – FDE, file encryption, database encryption). Protects data from unauthorized access in case of hardware or media theft.
• Encryption of data in transit (Data in Transit): Protection of data transmitted over computer networks (such as the Internet). Protocols such as TLS/SSL (used in HTTPS), SSH, VPN use encryption to protect communications from eavesdropping.
• End-to-End Encryption (E2EE) of communications: Ensuring that only the sender and receiver of a message can read it, without the possibility of access by intermediaries (e.g., the communication service provider). Used, for example, in messaging services Signal or WhatsApp.
• Protecting passwords and credentials: Store passwords in encrypted form or (more often) in the form of cryptographic hashes.
• Digital Signatures: Using asymmetric cryptography to confirm the authenticity and integrity of digital documents.

The importance of key management

The security of an encryption system depends largely on the security of cryptographic keys. Effective key management – their generation, distribution, storage, rotation and invalidation – is key to maintaining data confidentiality. The loss or compromise of a private key can lead to security breaches.

Summary

Data encryption is a fundamental tool for ensuring the confidentiality of information in the digital world. By transforming data into an unintelligible form using algorithms and keys, it protects it from unauthorized access during both storage (data at rest) and transmission (data in transit). The use of strong encryption algorithms and proper key management are essential for effective protection of sensitive data.