TLS (Transport Layer Security)
Ziti's Data Encryption and Decryption
In advance, I will give a basic introduction on the historical development of SSL and TLS and their significance in network security.
Then, I will demonstrate a simple ziti's data encryption and decryption simulation.
- SSL (Secure Sockets Layer): An early encryption protocol developed by Netscape, which has now been replaced by TLS.
- TLS (Transport Layer Security): The successor to SSL, providing a more secure encryption protocol.
- Encryption: Ensures that data is not intercepted or altered during transmission.
- Authentication: Ensures the trustworthiness of the communicating parties.
- Data Integrity: Ensures that data is not modified during transmission.
- Symmetric Encryption: Uses the same key for both encryption and decryption (e.g., DES \ AES).
- Asymmetric Encryption: Uses a pair of public and private keys for encryption and decryption (e.g., RSA).
- Key Exchange Protocol: Ensure secure exchange of symmtric encryption key (e.g., Diffie-Hellman).
- Description: Never publicly released due to serious security issues.
- Improvements:
- Introduced basic encryption mechanisms. Supported symmetric encryption and digital certificates.
- Vulnerabilities:
- Several known security vulnerabilities, such as insecure key exchange mechanisms.
- Did not support Message Authentication Codes (MACs) to verify data integrity.
- Improvements:
- Addressed multiple security issues from SSL 2.0, improving encryption algorithms and protocol design.
- Introduced a more secure handshake process.
- Supported Message Authentication Codes (MACs), enhancing data integrity protection.
- Vulnerabilities:
- Despite improvements in security, SSL 3.0 still had some issues, such as the POODLE attack.
- Improvements:
- Added support for HMAC (Hash-based Message Authentication Code).
- Vulnerabilities:
- Still had some security issues, such as the CRIME and BEAST attacks.
- Improvements:
- Prevented packet replay attacks by adding IV (Initialization Vector) randomization.
- Enhanced security for symmetric encryption modes, supporting AES encryption.
- Vulnerabilities:
- Improved over TLS 1.0 but still had some known security risks, such as the Lucky Thirteen attack.
- Improvements:
- Introduced new message authentication algorithms (e.g., SHA-256).
- Supported stronger encryption algorithms (e.g., AES-GCM).
- Improved integrity protection mechanisms.
- Enhanced compatibility with older versions.
- Vulnerabilities:
- Although TLS 1.2 provided many security improvements, it still faced some attack threats, such as the POODLE attack.
- Handshake Overview:
- ClientHello: TLS version, cipher suite, client random number, compression method.
- ServerHello: TLS version, cipher suite, server random number, additional information.
- ServerCertificate: Certificate, public key(RSA).
- ServerKeyExchange: Public key(DH), parameter(DH).
- CertificateRequest: Optional.
- ServerHelloDone: Ending mark.
- ClientCertificate: Certificate(if requested by server), public key.
- ClientKeyExchange: Pre-master secret key(RSA, encrypted by server's public key), public key(DH).
- CertificateVerify: Verify possession of the private key in the certificate.
- ChangeCipherSpec: Use new encryption method.
- Finished: Ending mark.
- Improvements:
- Simplified the handshake process, reducing round trips and improving performance.
- Defaulted to Perfect Forward Secrecy (PFS).
- Removed outdated and insecure encryption algorithms and protocol features (e.g., RC4, MD5, SHA-1).
- Enhanced data encryption and authentication, providing stronger security assurances.
- Vulnerabilities:
- TLS 1.3 was designed with a focus on security, and currently has no major security vulnerabilities, though it continues to be reviewed and improved.
- Handshake Overview:
Click here: Model Description
Click here: Model Simulation