What are the best practices for encrypting and decrypting data in transit and at rest?

1 Data in transit vs data at rest

Data in transit refers to data that is moving between different locations, such as from a source to a destination, or from a client to a server. Data at rest refers to data that is stored in a persistent or semi-persistent state, such as in a database, a file system, or a cloud storage service. Both types of data need to be encrypted to prevent unauthorized access or interception, but they may require different encryption methods, protocols, and keys depending on the context and the level of security needed.

2 Symmetric vs asymmetric encryption

Symmetric encryption uses the same key to encrypt and decrypt data, while asymmetric encryption uses a pair of keys: a public key to encrypt data and a private key to decrypt data. Symmetric encryption is faster and simpler, but it requires a secure way to share and manage the key among the parties involved. Asymmetric encryption is more secure and scalable, but it is slower and more complex, and it requires a reliable way to verify the identity and authenticity of the parties involved. A common practice is to use a combination of both encryption types, such as using asymmetric encryption to exchange a symmetric key, and then using symmetric encryption to encrypt and decrypt the data.

3 Key management

Key management is an essential process for ensuring the security and availability of encrypted data, but it also presents some challenges and risks, such as key loss, key compromise, key misuse, or key overhead. To mitigate these risks, it is best to use strong and random keys that are hard to guess or crack; use different keys for different purposes; employ a secure and centralized key management service or system that supports encryption standards, access control, logging, and backup; regularly rotate the keys to reduce the exposure of encrypted data; and revoke keys to invalidate them in case of key compromise or data breach.

4 Encryption standards and protocols

Encryption standards and protocols are the rules and specifications that define how encryption and decryption are performed, such as the algorithms, the modes, the formats, the keys, and the messages. These standards are important for ensuring compatibility, interoperability, and compliance of encryption and decryption across different platforms, systems, and applications. To ensure security and efficiency, it's best to use well-known and widely adopted encryption standards such as AES, RSA, SSL/TLS or HTTPS. Additionally, it's important to use the latest versions of these standards which have fixed known vulnerabilities. It's also important to use the appropriate encryption standards for the specific use case and scenario. For instance, SSL/TLS should be used for data in transit and AES should be used for data at rest. Finally, make sure you use the proper encryption modes and configurations such as authenticated encryption or padding.

5 Encryption testing and monitoring

Encryption testing and monitoring are activities of verifying, validating, and evaluating the encryption and decryption processes, such as the functionality, the performance, the security, and the compliance. These activities are essential for ensuring the quality and reliability of encryption and decryption, as well as detecting and resolving any issues or errors that may occur. To this end, it is recommended to use encryption testing tools and methods that can simulate, measure, and analyze the encryption and decryption processes. Additionally, encryption monitoring tools and methods should be employed to track, record, and report the encryption and decryption activities. Moreover, encryption testing and monitoring should be done regularly and periodically before and after deploying or updating encryption/decryption or during/after encrypting/decrypting data in order to identify and address any encryption/decryption issues or errors.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?