What is TLS Email Encryption?

• Symmetric Encryption: This method uses a single key for both encryption and decryption. Common symmetric encryption algorithms include Advanced Encryption Standard (AES).

• Asymmetric Encryption: This approach involves a pair of keys – a public key for encryption and a private key for decryption. RSA (Rivest-Shamir-Adleman) is a widely used asymmetric encryption algorithm.

• Hash Functions: This function generates a fixed-size hash value from input data, ensuring data integrity. Common hash functions include SHA–256 (Secure Hash Algorithm).

The TLS handshake is the process that establishes a secure connection between the two email servers. It includes:

• Client Hello: The client initiates the handshake by sending a “Client Hello” message, specifying supported encryption algorithms and protocols.

• Server Hello: The server responds with a “Server Hello” message, selecting the encryption algorithm and protocol.

• Certificate Exchange: The server provides its digital certificate, verified by a trusted Certificate Authority (CA), to authenticate its identity.

• Key Exchange: Both parties exchange cryptographic keys to establish a secure session.

• Finished Message: The handshake concludes with both parties sending a “Finished” message, confirming establishing a secure connection.

Digital certificates are electronic documents that verify the identity of the communicating parties. They are issued by trusted Certificate Authorities and contain the public key, subject information, and the CA’s digital signature. Digital certificates ensure the authenticity and integrity of the email servers.

TLS has undergone several iterations, with improvements in security and performance. The most commonly used versions are:

• TLS 1.0: The initial version is now largely deprecated due to security vulnerabilities.

• TLS 1.1: An improved version with enhanced security features.

• TLS 1.2: Widely adopted for its strong security and flexibility.

• TLS 1.3: The latest version offers improved performance and security by reducing the number of handshake messages and deprecating insecure algorithms.

TLS Email Encryption ensures that email content remains confidential by encrypting the data during transmission. Only the intended recipient can decrypt and access the message, protecting it from unauthorized access.

TLS provides a way to detect any alterations in the data during transmission. Hash functions and digital signatures ensure the email content remains unchanged from sender to recipient.

Digital certificates and the TLS handshake process authenticate the identity of the communicating parties, preventing man-in-the-middle attacks and ensuring that emails are exchanged with trusted servers.

TLS Email Encryption helps organizations comply with data protection regulations and industry standards by safeguarding sensitive information during email transmission.