In the early days of the Internet, some aspects, such as data security, were not as important as they are today. All communication was transmitted from one computer to another openly and without encryption. We could compare it to a postcard: any postman can read it..
The TLS protocol , also known as SSL / TLS, introduced encryption of transmitted content . To continue the analogy, such encryption would be the equivalent of a sealed envelope that only its rightful recipient can read.
TLS is the acronym for Transport Layer Security, which translates into Spanish as transport layer security . This name refers to the transport layer of the TCP / IP model. TLS is a process that encrypts Internet data streams so that only their legitimate recipients can read them. It was previously known as SSL (Secure Socket Layer). Since this abbreviation is still more popular than TLS, it is common for us to refer to TLS by the double designation SSL / TLS..
TLS encrypts by symmetric encryption all data traffic that takes place through TCP.
Find comprehensive information on encryption methods in our guide..
Although it sounds easy in practice, the reality is more complicated. The main problem is that the server must communicate the key to the client, and additionally it must do so before the communication is secured with TLS. If you regularly send encrypted files by mail, you will know this problem: you encrypt a file and then you must share the password with the recipient, for example, by phone.
To solve this problem, the TLS protocol use the following method:
The reason that asymmetric cryptography is only used for the transmission of the session key (but not for the encryption of the data stream itself) is the disadvantage that it has in speed: asymmetric cryptography is relatively slow and would delay the data communication.
TLS is a simple solution to make data traffic more secure on the web, since it does not require the parties to encrypt the content themselves, such as the data of a form. Instead, it is sufficient that the traffic occurs through the TLS protocol , regardless of the operating system and computer applications used by those involved. During transmission, all data streams are automatically encrypted.
The price of this security is a slightly slower connection, as the process stages just described? Certificate, random number and key exchange? it is very demanding at the computational level.
As we have explained, TLS can be used universally, regardless of the application or operating system. As a consequence, many application protocols have a secure version of TLS. The designation scheme is very simple: when the protocol communicates over TLS, the letter S is placed after the protocol name.
The most important scope of TLS is the World Wide Web or, more specifically, the HTTP protocol. Its encrypted variant is called HTTPS .
Other common application cases are:
OpenVPN, a free software for establishing a virtual private network (VPN), also uses the TLS protocol .
Some important applications of TLS are:
This list is not exhaustive. You can find information on the uses of TLS in the English Wikipedia article TLS App Comparison .
TLS is not totally safe from attacks and leaks. Some known points of attack are:
In addition, an attempt was made to avoid the emergence of a fully secure TLS encryption so that authorities could inspect encrypted communications, for example if they were related to financial transactions or criminal activities. One of the organizations that worked the most for TLS to have such a weak point was the ETSI (European Telecommunications Standards Institute).