| No | Expression | Explanation |
| 1 | Virtual Private Networking (VPN) | Provides the medium to use the public Internet backbone as an appropriate channel for private data communication. |
| 2 | The secure socket layer Protocol(SSL) | A communication system that ensures privacy when communicating with other SSL-enabled products. |
| 3 | Transport Layer Security (TLS) | A popular mechanism for enhancing TCP communications with privacy and authentication |