Today I took leave from my work and learned something different. That different thing is “Security Protocols ”

Many security protocols have been developed as VPNs, each offering differing levels of security and features. Among the more common are:

  • Secure Sockets Layer (SSL) and Transport Layer Security (TLS): SSL and TLS are used extensively in the security of online retailers and service providers. These protocols operate using a handshake method. As IBM explains, “A HTTP-based SSL connection is always initiated by the client using a URL starting with https:// instead of with http://. At the beginning of an SSL session, an SSL handshake is performed. This handshake produces the cryptographic parameters of the session.” These parameters, typically digital certificates, are the means by which the two systems exchange encryption keys, authenticate the session, and create the secure connection.
  • Secure Shell (SSH): SSH creates both the VPN tunnel and the encryption that protects it. This allows users to transfer information unsecured data by routing the traffic from remote fileservers through an encrypted channel. The data itself isn’t encrypted but the channel its moving through is. SSH connections are created by the SSH client, which forwards traffic from a local port one on the remote server. All data between the two ends of the tunnel flow through these specified ports.
  • Point-to-Point Tunneling Protocol (PPTP): PPTP is a ubiquitous VPN protocol used since the mid 1990s and can be installed on a huge variety of operating systems has been around since the days of Windows 95. But, like L2TP, PPTP doesn’t do encryption, it simply tunnels and encapsulates the data packet. Instead, a secondary protocol such as GRE or TCP has to be used as well to handle the encryption. And while the level of security PPTP provides has been eclipsed by new methods, the protocol remains a strong one, albeit not the most secure.
  • Layer 2 Tunneling Protocol (L2TP)/IPsec: The L2TP and IPsec protocols combine their best individual features to create a highly secure VPN client. Since L2TP isn’t capable of encryption, it instead generates the tunnel while the IPSec protocol handles encryption, channel security, and data integrity checks to ensure all of the packets have arrived and that the channel has not been compromised.