In the sprawling vastness of the digital universe, where data zips through like comets in the night sky, there exists an omnipresent sentinel, often unnoticed but indispensable—HTTPS. Like an enigmatic shield, it envelops our digital exchanges, ensuring they traverse cyberspace unfettered and untouched by malevolent entities. But what is this guardian, and why is its role so paramount in our daily digital interactions?

In this article:

As we increasingly embed the digital sphere into our lives, entrusting it with our most intimate secrets and essential transactions, understanding the mechanisms that guard this space becomes imperative. HTTPS, often represented by a small padlock icon in your browser’s address bar, is more than just a technical acronym—it’s the bedrock of secure online communication.


What is HTTPS?

At its core, HTTPS (Hyper Text Transfer Protocol Secure) is an evolution of the HTTP, a protocol that facilitates data transfer on the web. Imagine a highway—while HTTP would represent the lanes guiding the traffic, HTTPS would be the fortified lanes, where armored vehicles (representing your data) traverse securely.

The ‘S’ in HTTPS, signifying ‘Secure’, is powered by TLS (Transport Layer Security) or its predecessor, SSL (Secure Sockets Layer). These cryptographic protocols act like digital cloaks, encrypting the data exchanged between a user’s browser and the server. This encryption ensures that any malevolent entity intercepting the data would find it unintelligible, akin to intercepting a coded message without the decoder. As a result, whether you’re inputting credit card details, sharing personal stories, or even just browsing, HTTPS ensures that prying eyes are kept at bay, preserving the sanctity and privacy of your online interactions.

Difference between HTTP and HTTPS

HTTPS URLs begin with “https://” and use port 443 by default, whereas, HTTP URLs begin with “http://” and use port 80 by default. Read our article Difference between HTTP and HTTPS.

The History of HTTPS: Chronicles of the Digital Safeguard

In the digital tapestry that records the story of the World Wide Web, one emblem shines with a particular resonance: the padlock of HTTPS. Its inception wasn’t a sudden epiphany but rather a compelling response to the ever-evolving dance between innovation and vulnerability. So, let’s embark on a riveting odyssey, charting the course of HTTPS from its nascent inklings to its role as the vanguard of the digital domain.


The late 1980s and early 1990s saw the internet blossoming from a niche military and academic network into a burgeoning public platform. This transformation came with its pitfalls. While HTTP (Hyper Text Transfer Protocol) was adept at transferring data, it did so in clear text. This was akin to sending letters in transparent envelopes—anyone with a little knowledge and malice could intercept, read, or even alter the contents. As e-commerce platforms, electronic banking, and personal blogs began to proliferate, the need for a secure conduit became not just desirable but paramount.


Enter Netscape Communications. In 1994, aiming to bolster the safety of its pioneering Navigator browser, Netscape introduced SSL (Secure Sockets Layer). SSL was groundbreaking. It provided a way to encrypt the data packet journey from the user’s computer to the server, ensuring the sanctity of the transmitted information. The inaugural version, SSL 1.0, was internal, but by 1995, SSL 2.0 was publicly released. Though a landmark, it was not without its flaws. By 1996, SSL 3.0 emerged, addressing many vulnerabilities of its predecessor.


The evolution didn’t stop there. The IETF (Internet Engineering Task Force) took the baton, refining SSL into what we now recognize as TLS (Transport Layer Security). TLS 1.0, essentially SSL 3.1 in spirit, was released in 1999. Subsequent iterations, including TLS 1.1 in 2006, TLS 1.2 in 2008, and TLS 1.3 in 2018, offered enhanced security, performance, and privacy, ensuring HTTPS remained contemporary amidst rapidly advancing cyber threats.

HTTPS as an SEO Signal

But it’s worth noting that while technology evolved, adoption wasn’t always swift. Many sites were reluctant to make the shift, citing performance concerns or the cost of certificates. It took conscious pushes, like Google’s decision in 2014 to favor HTTPS sites in search rankings or the advent of free certification authorities like Let’s Encrypt, to catalyze the widespread embrace of HTTPS.

From its embryonic conception in the corridors of Netscape to its present-day ubiquity, HTTPS has transitioned from being a luxury to a cornerstone of secure digital communication. In this chronicle, we don’t just witness the maturation of a protocol but the manifestation of the internet’s inherent capability: to adapt, evolve, and safeguard its denizens in an ever-shifting landscape.

The Mechanisms of Encryption: Dive deep into TLS and SSL

Amid the bustling thoroughfares of the digital metropolis, one mechanism stands sentinel, ensuring that our most confidential conversations and transactions are whispered in coded dialects, impermeable to eavesdroppers. This protective aegis, founded on the tenets of TLS and its predecessor SSL, represents the esoteric art and science of encryption. In this chapter, we pull back the curtain on these cryptographic maestros, delving into their intricate symphonies of security.

SSL: The Prologue

The tale begins with the Secure Sockets Layer (SSL). Envisioned by Netscape in the mid-’90s, SSL’s objective was to ensure privacy, authentication, and data integrity in Internet communications. It accomplished this through a layered approach:

  • Record Protocol: At its base, this protocol was responsible for packaging the higher-level data into blocks, compressing it, and appending a unique message digest.
  • Handshake Protocol: Before data exchange began, this protocol facilitated the mutual agreement on encryption standards and the exchange of cryptographic keys. Imagine two diplomats setting ground rules before entering sensitive negotiations.
  • Alert Protocol: A signaling mechanism, that informs the other party of any potential issues or the impending closure of a session.

TLS: The Evolution

As digital ne’er-do-wells grew more sophisticated, SSL evolved into its more robust progeny: Transport Layer Security (TLS). At its core, the philosophy remains unchanged—secure data through encryption. But the tools in its arsenal have expanded and refined:

  • Key Exchange and Handshake: Like its SSL forebearer, TLS also starts with a handshake. Here, both parties—typically a web browser and a server—agree on which encryption algorithm to use. They also exchange asymmetric public keys, the foundational pillars of the encryption process. This mutual introduction ensures both sides are genuinely who they claim to be.
  • Symmetric Session Keys: Once the handshake is cemented, both parties use their respective private keys to decipher the shared public keys and generate a unique session key. This symmetric key, known only to these two parties for that session, will be used to encrypt and decrypt the data during the exchange.
  • Data Transfer: With the session key in place, data is encrypted using the agreed-upon algorithm and dispatched. To any prying entity, this data appears as gibberish—its true form obscured by the cryptographic veil.
  • Closure and Resumption: Once the session concludes, the keys are discarded. However, for efficiency, the session’s parameters might be cached. If the parties converse again, they can skip parts of the handshake, expediting the process.

The Symphony of Algorithms

The efficacy of TLS and SSL is anchored in the cryptographic algorithms they employ. From RSA and Diffie-Hellman for key exchanges to AES and ChaCha20 for data encryption, these algorithms, with names evoking cryptic incantations, serve as the bulwarks against intrusion.

In the end, while terms like asymmetric encryption, cipher suites, and elliptic curve cryptography might sound arcane, they are the unsung heroes in our daily digital dalliances. Much like a maestro directing an orchestra, TLS and SSL deftly maneuver these components to create a harmonious, secure digital experience. In this symphony of encryption, every note, pause, and crescendo is meticulously crafted, ensuring our digital song remains both melodious and private.

» To read next: What is the difference between port 80 and port 443?

HTTP is not encrypted and is vulnerable to man-in-the-middle and eavesdropping attacks, which can let attackers gain access to website accounts and sensitive information, and modify web pages to inject malware or advertisements. HTTPS is designed to withstand such attacks and is considered secure against them (with the exception of older, deprecated versions of SSL).


HTTPS uses the TCP well-known port number 443 instead of port 80, which is used by HTTP. HTTPS is not the same as Secure Hypertext Transfer Protocol (S-HTTP).

External references: