You can freely build on How Netscape Created the Secure Socket Layer (SSL) for Web Security

What this patent covers

This patent describes a software layer that sits between an application, like a web browser, and the network transport protocols. It provides a socket interface that allows applications to send and receive data without needing to know the technical details of the encryption process. When data is sent, the code intercepts it, encrypts it, and passes it to the transport layer. When data is received, it decrypts the information before handing it off to the application, ensuring that sensitive data like credit card numbers remains private during transit.

What is now free to use

All 0 claims of US 5657390 are in the public domain. Specifically:

The 0 dependent claims add narrowing limitations and are also free.

What is NOT covered

Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.

• Does not cover specific encryption algorithms like RSA or AES individually.

• Does not cover the physical hardware or network cabling used to transmit data.

• Does not cover the underlying TCP/IP protocol stack itself.

• Does not cover authentication methods like digital certificates not described in the specific socket-layer implementation.

Who is building on this today

The technology evolved into TLS (Transport Layer Security), which is maintained by the IETF. Modern browser vendors like Google, Mozilla, and Apple, as well as cloud infrastructure providers like Cloudflare and AWS, continue to build upon these foundational security concepts.

Products built on expired version of this technology

How to cite this patent in your documentation

Netscape Communications Corp. US Patent 5657390. Secure socket layer application program apparatus and method. Granted 1997, expired 2015. Now in the public domain.

Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.

PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.