What Is Data Encryption?

5 min. read

Data encryption, critical to data protection, converts data into another form or code to prevent unauthorized access, helping organizations to maintain privacy and meet compliance mandates. It uses an algorithm (or cipher) to transform readable data, known as plaintext, into unreadable data, known as ciphertext. Only those with the correct secret key can decrypt the ciphertext back into plaintext and access the original information.

Data Encryption Explained

Data encryption in cloud security ensures that sensitive information remains protected and inaccessible to unauthorized parties. At its core, data encryption involves transforming plaintext data into an unreadable format, called ciphertext, using a specific algorithm or cipher. The encryption process requires a secret key for both encryption and decryption, with symmetric encryption using the same key for both operations, and asymmetric encryption employing a public key for encryption and a private key for decryption.

For cloud security, data encryption plays a vital role in securing data at rest and in transit. Advanced encryption techniques can provide staunch protection against breaches and unauthorized access. Additionally, to fortify security, organizations can implement key management practices, including secure key storage, rotation, and distribution.

Types of Encryption

Two primary types of encryption address different security and logistical challenges of data protection and communication. While organizations may use them separately, they’re often combined to overcome the challenges of key distribution and performance needs.

Symmetric Encryption (or Private Key Encryption)

Symmetric encryption, also known as private key encryption, uses the same key for both encryption and decryption. In other words, the sender and receiver share a single secret key to encrypt and decrypt data. The technique offers a fast and efficient way to secure large volumes of data, as it requires less computational overhead compared to asymmetric encryption. Symmetric encryption has a downside, though, challenged by the secure distribution and management of the shared key, as unauthorized access to this key can compromise the encrypted data.

Common symmetric encryption algorithms include Advanced Encryption Standard (AES) and Data Encryption Standard (DES).

Asymmetric Encryption (or Public Key Encryption)

Asymmetric encryption, or public key encryption, relies on two distinct keys — a public key for encryption and a private key for decryption. The public key can be openly shared, while the private key must remain confidential. Asymmetric encryption solves the key distribution problem in symmetric encryption, as only the private key needs to be securely stored. But asymmetric encryption, as with symmetric encryption, has a downside in that it requires more computational resources and is generally slower than symmetric encryption. RSA (Rivest-Shamir-Adleman) is a widely-used asymmetric encryption algorithm.

What Are the Benefits of Data Encryption?

Organizations find themselves navigating an intricate web of data, from customer information to trade secrets. This digital landscape, while rich with opportunity, also presents vulnerabilities. Data encryption emerges as a defender, fortifying business data and ensuring companies can operate confidently and securely.

One of the primary benefits of data encryption is protecting sensitive information. When data is encrypted, it transforms into an unreadable format, accessible only to those with the correct decryption key. This means that even if malicious actors were to breach a system, the stolen data would remain a jumble of cryptographic text, effectively useless without the corresponding key. This layer of security is paramount not only for safeguarding proprietary information but also for maintaining customer trust. Clients and customers are more likely to engage with organizations they believe will responsibly handle their personal and financial information. A breach can tarnish a company’s reputation, lead to financial losses, and even result in legal consequences.


While safeguarding data, encryption contributes to regulatory compliance, addressing requirements outlined in laws like the General Data Protection Regulation (GDPR) in the European Union and the Health Insurance Portability and Accountability Act (HIPAA) in the U.S. By employing encryption, organizations demonstrate their commitment to data privacy and security.

Encrypted communication, especially in sectors like finance and healthcare, ensures that sensitive data exchanged between entities remains confidential and unaltered. Data encryption shields organizations from external threats and positions them as trustworthy stewards of data in the eyes of clients and regulators. By employing strong encryption practices, organizations can stay compliant, avoiding fines and potential legal battles.

Data Encryption Use Cases

Data encryption protects information, ensuring privacy and security across different sectors. The protection provided maintains data integrity, as well as data loss prevention, by making stolen data unusable and reducing the impact of a data breach. Common applications of data encryption include:

  • Securing communication — emails, chats, calls — from unauthorized interception
  • Enhancing cloud data security by ensuring sensitive data is safe from external theft and modification
  • Maintaining confidentiality of sensitive data and compliance with regulations like HIPAA, PCI-DSS, GDPR, and other regulations
  • Safeguarding credit cards and bank details during e-commerce and online banking
  • Keeping data at rest secure, especially files and databases on data storage devices (hard drives, SSDs) in the event they’re lost or stolen
  • Verifying message authenticity and origin with digital signatures (using asymmetric encryption)
  • Maintaining privacy of internet traffic, even on untrusted networks, via VPN
  • Using hashed (and salted) passwords instead of plaintext passwords
  • Ensuring only the sender and receiver can read the content transmitted via messaging apps with end-to-end encryption
  • Securing cryptocurrencies like Bitcoin with encryption for transaction and new unit creation protection
  • Protecting copyrighted content (e-books, music, video) from unauthorized reproduction or use
  • Securing data transmission and storage on IoT devices

Key Selection

Selecting the appropriate cryptographic and key management algorithms for an application requires a clear understanding of the application's objectives and security requirements. For instance, if the goal is to protect stored data, choose an algorithm suite that focuses on data at rest security. Conversely, applications that transmit and receive data should prioritize algorithm suites that emphasize data in transit protection.

To determine the optimal key management approach, start by comprehending the application's security objectives, which will guide the selection of suitable cryptographic protocols. The application may necessitate:

  • Confidentiality for both data at rest and data in transit
  • End device authentication
  • Data origin authenticity
  • Data integrity during transit
  • Keys for generating data encryption keys

Having established the application's security needs, organizations can identify the required protocols and algorithms. With a clear understanding of these protocols and algorithms, teams can proceed to define the various key types that support the application's objectives, ensuring robust security and optimal performance.

Data Encryption and Algorithms

Choosing the right encryption algorithm is an early and important step in ensuring data privacy and protection against potential threats, including those posed by quantum computing. You’ll want to consider organizational factors such as security and compliance with industry standards, performance, key management, compatibility, scalability, and future-proofing against emerging threats.

AES-256 with Galois Counter Mode (GCM)

AES-256 with Galois Counter Mode (GCM) is a widely recommended option, as it provides strong encryption and authentication. GCM is an authenticated encryption mode that combines the high-performance, symmetric key block cipher, AES-256, with an efficient message authentication code, ensuring both data confidentiality and integrity.

ChaCha20 and Poly1305

Another viable choice is the combination of ChaCha20 and Poly1305. ChaCha20 is a stream cipher that offers high-speed encryption, while Poly1305 serves as a cryptographic message authentication code, providing data integrity. Together, these algorithms create a secure authenticated encryption with associated data (AEAD) scheme, ensuring confidentiality and integrity of the encrypted data.

Encryption Best Practices

  • Employ end-to-end encryption for sensitive communications.
  • Secure data at rest and in transit.
  • Apply multi-factor authentication for access control.
  • Update cryptographic libraries and protocols.
  • Perform regular security audits and vulnerability assessments.
  • Train staff on encryption policies and practices.
  • Unless encryption keys are encrypted, don’t store them next to the sensitive data they encrypt.
  • Regularly rotate encryption keys.
  • Adhere to industry standards and regulatory requirements, and stay informed about emerging cryptographic technologies and practices to maintain strong data protection.

Data Encryption FAQs

Convergent encryption is a cryptographic technique that generates identical ciphertext for identical plaintext data, given the same encryption key. This method utilizes a deterministic process, often employing the plaintext data's hash as the encryption key.

By producing the same ciphertext for duplicate data, convergent encryption enables efficient storage and deduplication in cloud environments. While convergent encryption offers storage optimization benefits, it also presents security risks. Attackers with knowledge of the plaintext can potentially compute the hash, derive the encryption key, and confirm the existence of specific data in the encrypted storage, potentially leading to privacy and confidentiality breaches.

Cryptographic hash functions are mathematical algorithms that take an input of arbitrary length and generate a fixed-length output, known as the hash or digest. Key characteristics making cryptographic hash functions ideal for ensuring data integrity and security include:

  • Determinism, meaning the same input always produces the same hash
  • Inability to derive the original input from the hash, ensuring one-way functionality.
  • Strong collision resistance, making it difficult to find two different inputs capable of producing the same hash

Commonly used cryptographic hash functions include SHA-256, SHA-3, and BLAKE2, which are employed in various applications like digital signatures, data integrity verification, and password storage.

Online transactions security refers to the measures employed to protect credit card information, bank details and other sensitive data during e-commerce and online banking activities. Security is achieved through encryption, secure communication protocols, and authentication mechanisms. Payment Card Industry Data Security Standard (PCI-DSS) is a set of requirements that ensures the security of cardholder data during processing, storage, and transmission. Implementing secure socket layer (SSL) or transport layer security (TLS) protocols also helps safeguard the data exchange between users and servers.

Data at rest protection involves securing files and databases stored on data storage devices or cloud storage. Encryption plays a foundational role in data at rest protection, as it renders data unreadable without an appropriate decryption key.

Access controls, such as strong passwords and multifactor authentication, enhance the security of stored data by restricting unauthorized access. Regular data backups and secure disposal of old storage devices also contribute to the protection of data at rest.

Cloud storage security encompasses the measures taken to protect data stored in the cloud from unauthorized access, modification, and deletion. It involves encryption for data at rest and in transit, strong access controls, and comprehensive monitoring and logging of user activities. Additionally, cloud storage security includes adherence to regulatory compliance, ensuring data privacy and working with trusted cloud service providers that offer secure infrastructure, regular security updates, and vulnerability management.

Adopting a shared responsibility model, where both the cloud service provider and the user take proactive steps to secure data, enhances cloud storage security.

Authentication is the process of verifying the identity of a user, device, or system attempting to access a protected resource. It ensures that only authorized entities gain access to sensitive data and services. Common authentication methods include:

  • Passwords
  • Security tokens
  • Biometric identifiers
  • Digital certificates

Multi-factor authentication (MFA) combines two or more of these methods, significantly enhancing security by requiring multiple proofs of identity.

A virtual private network (VPN) is a technology that creates an encrypted connection between a user's device and a remote server, typically operated by a VPN service provider. The secure connection enables users to transmit data over the internet as if they were connected directly to a private network, maintaining privacy and confidentiality, even on untrusted networks.

VPNs can be used to access restricted content, bypass censorship, and protect sensitive data from being intercepted by malicious actors. VPNs are also used by businesses to enable remote access to corporate resources, ensuring secure communication between employees and the organization's network.

EaaS is a model in which users subscribe to a cloud-based encryption service without having to install encryption on their systems. Organizations using EaaS benefit from:

  • Encryption at rest
  • Encryption in transit (TLS)
  • Key handling and cryptographic implementations taken care of by encryption service
  • Providers can add more services to interact with the sensitive data