Data encryption is a crucial security technique that converts readable information (plaintext) into an unreadable format (ciphertext) to protect sensitive data from unauthorized access. This transformation ensures that only individuals with the correct decryption key can access the original data, thereby maintaining confidentiality and integrity.

In mobile applications, data exists in three states: at rest, in transit, and in use. Effective data encryption addresses all these states to prevent data breaches and unauthorized access. For example, encrypting data at rest protects stored information on devices, while encrypting data in transit secures information being transmitted over networks.