Ssl encryption how does it work

The process by which that sessions key is agreed upon is called a handshake, since it's the moment when the two communicating computers introduce themselves to each other, and it's at the heart of the TLS protocol.

The handshake process is quite complex, and there are a number of variations allowed by the protocol. The following steps provide a broad outline that should give you a sense of how it works. This article at SSL. As its name implies, the session key is only good for the course of a single, unbroken communications session.

If for some reason communications between client and server are cut off — due to a network problem, for instance, or because the client is idle for too long — a new handshake will be required to establish a new session key when communication is re-established. Let's return to the concept of an SSL certificate. But their purpose goes beyond just supplying the key itself; they also authenticate that the key is in fact associated with organization offering it to the client.

How does this work? Certificates are issued by Certificate Authorities CAs , who serve as the equivalent of a passport office when it comes to confirming identities. Organizations that want to offer services encrypted by TLS must purchase certificates from CAs, who in turn verify that the organizations are who they claim to be.

For instance, if you wanted to buy a certificate to secure a website at example. That way, if someone connects to example. This can prevent man in the middle attacks. Notice that we used the phrase "trusted CA" in that last paragraph. Anyone can set themselves up as a certificate authority; how can you tell which ones perform the due diligence needed to authenticate their customers?

Fortunately, the job of figuring that out is mostly taken care of by software manufacturers. The decisions on which CAs to trust have high stakes, as a showdown between Google and Symantec over what Google felt were Symantec's lax standards made clear.

The standard that defines SSL certificates is called X. This standard allows certificates to carry a lot of information beyond just the public key and the confirmed identity of the certificate owner; DigiCert is a CA whose knowledge base has a detailed breakdown of the standard. Almost all of the exchange and confirmation of information detailed above takes place behind the scenes as you communicate with servers that offer TLS-encrypted connections.

The checker will return a host of information about the tested site's certificate, including the server type, which web browsers will and won't trust the certificate, the issuer, the serial number, and the expiration date. Most SSL checkers are free services offered by CAs as marketing tools for their wares; many will, for instance, allow you to set an alert for when an inspected certificate will expire, on the assumption that it's your certificate and you'll be in the market for a new one as that date approaches.

If you're looking for a somewhat less commercial alternative, check out the SSL checker from Qualys SSL Labs , which provides a particularly robust collection of information on inspected websites.

TLS 1. They are digital passports that provide authentication to protect the confidentiality and integrity of website communication with browsers.

This secure connection cannot be established without the SSL certificate, which digitally connects company information to a cryptographic key. Any organization that engages in ecommerce must have an SSL certificate on its web server to ensure the safety of customer and company information, as well as the security of financial transactions. A browser or server attempts to connect to a website i.

If so, it sends a message to the web server. The web server sends back a digitally signed acknowledgement to start an SSL encrypted session. Extended Validation EV and Organization Validated OV certificates are widely used by organizations that want to provide their online customers with strong encryption technology and identity assurance.

Encryption ensures that customer data like credit card information and passwords cannot be stolen as it is transmitted. The amount of verification checking behind the various certificate types is reflected in the pricing variations.

The increased vetting, particularly for EV and OV certificates, is what makes these high assurance certificates more expensive. EV certificates are preferred by most online users because they come with the most comprehensive verification checking, which includes domain verification as well as crosschecks that tie the entity to a specific physical location. This type of verification leaves a detailed paper trail providing customers with recourse should fraud take place while transacting on that website.

EV certificates are distinguished with a locked padlock, organization name and sometimes the country ID in the web address bar in most major browsers.

In a key pair, one key is shared with anyone who is interested in a communication. This is called Public Key. The other key in the key pair is kept secret and is called Private Key. Here, the keys referred to a mathematical value and were created using a mathematical algorithm which encrypts or decrypts the data. In the asymmetric cryptography, the data can be signed with a private key, which can only be decrypted using the related public key in a pair.

In the symmetric cryptography, there is only one key which encrypts and decrypts the data. Both sender and receiver should have this key, which is only known to them. SSL uses symmetric cryptography using the session key after the initial handshake is done.

SSL protocol uses asymmetric and symmetric cryptography to transfer data securely.