Difference Between TLS and SSL

The use of computers in a variety of fields including e-commerce, medicine, education, etc requires the inevitable use of the Internet. This seems to be logical and practical and you may even wonder, how come this is related to our topic i.e. the difference between the TLS (Transport Layer Security) and the SSL (Secure Socket Layer). Yes, there exists a relation as these two are nothing but the internet protocols.

What is an Internet Protocol?

A protocol is set of instructions to carry out particular computer-related tasks and in this case, the internet protocols perform the actual message transfer, authentication procedures, etc. So we can say that without internet protocols, we cannot imagine our global message transfers or any other internet related activity. Some of the widely used Internet protocols are Hyper Text Transfer Protocol (HTTP), File Transfer Protocol (FTP), Transport Layer Security (TLS), Secured Socket Layer (SSL), Point to Point Protocol (PPP), Transfer Control Protocol (TCP), Simple Mail Transfer Protocol (SMTP), etc.  Among those protocols, the TLS and SSL perform data encryption and server authentication.

History of TLS and SSL

SSL is from Netscape and its first versions SSL v1.0 was not at all released. So we have been using SSL v2.0 since its release in the year 1995. A year later, it was replaced by the next version SSL v3.0. Later in 1996, TLS was introduced as an improved version of SSL v3.0. Probably, you may get the question that why it was not named as SSL v4.0! This is a reasonable question for a common man but when we think from the technical perspective, TLS is not just an enhancement of SSL v3.0 but is far more.

Which is the Predecessor, TLS or SSL?

The SSL is the predecessor of TLS and we can even take it like the latter is the improved version of the former protocol.  Even with the TLS, we can find many versions like TLS v1.1 and v 1.2. The same applies to SSL as well with the versions up to SSL v3.0. As with any software, the next version is an enhanced form of the previous to help its users in a better way.

Which is secure?

We have already discussed that the TLS is the successor and hence it is logical to say that is more secure. The SSL is vulnerable to POODLE and other issues that we would not encounter with the usage of TLS. The POODLE attack is something like extracting information even from an encrypted message and thus it nullifies the purpose of encryption. In a similar manner, the SSL v3.0 is vulnerable to BEAST attacks and therefore this is not a good choice when security comes into the picture. The BEAST attacks allow the eavesdroppers to get control over your accounts with certain websites and this attack is even possible with TLS v1.0. Therefore, it is a better idea to implement the TLS v2.0 to be safer from such intrusions.

When to choose SSL and when to choose TLS?

You might be asked to select an internet protocol encryption at a variety of circumstances such as when you configure your server or when you set up any of our client’s machines. At this point, you may think that the TLS is superior to SSL in terms of security and it is the successor to SSL. Therefore, most of us would go ahead and choose TLS. For those, I recommend you to wait and continue read below. While you select an internet protocol you should not only look & compare at the latest protocols but also its latest versions. Yes, just think that the server supports only TLS v1.0 and it does not support SSL v3.0 and it’s no use that you has chosen TLS for security purposes! As TLS v1.0 is susceptible to POODLE and BEAST attacks, it is a better idea to choose SSL v3.0 here. We can even argue that even SSL v3.0 also allows POODLE but when we compare both, SSL v3.0 is a better choice here.

What should you do when you encounter certificate issues?

As SSL is vulnerable to many online fraudulent attacks, IETF has deprecated the use of SSL v2.0 and v3.0 for security reasons. It is why we sometimes face issues while using servers that support only TLS certificates. These certificates are specific for each protocol versions and the certificate of one protocol version cannot be used with the other. For example, when your computer is operating with SSL v3.0 and the certificate issued by the server is TLS, then you cannot use it in your communications. It means that you could not successfully establish a communication with your server. Such an error can be overcome by just disabling SSL versions.

How to check whether your server uses SSL versions?

Just check whether your server uses any of the versions of SSL protocol. You can easily do it here – SSL Server Test.

Which is faster?

The TLS has two layers of operations while it establishes the communication. The first one is the Handshaking to authenticate the server and the second one is the actual message transfer. Therefore, it takes a little more time than the older SSL to establish connections and transfers.

Which is complex to manage on the server side?

The TLS require the installation of up-to-date certificates on our servers and we need to check its validity for communication to take place. But these need not be done manually as automated tools to do the same. Though we need certificates for SSL as well, it is not compatible with the TLS servers. For that compatibility & enhanced security, we rely on the little complex TLS protocol.

Backward compatibility

TLS is designed with backward compatibility whereas the SSL being the predecessor, we cannot expect it here.

It’s partially clear that TLS and SSL are different and it would be still more understandable when you look at the differences in a tabular form.

S.No	Concepts	Differences
		TLS	SSL
1	Released in the year	It was released in 1999.	SSL v2.0 was first released in 1995 and v3.0 in 1996. SSL v1.0 was not released to the public.
2	Based on which protocol?	It’s based on the SSL v3.0 protocol and with improvements.	No such basis. It was developed with communication needs and related issues.
3	The predecessor of which protocol?	Might be the predecessor to few latest improvements in the same protocol.	The predecessor of TLS.
4	Vulnerable attacks	TLS v1.0 is vulnerable to BEAST attacks. But it never allows POODLE attacks.	SSL v2.0 & v3.0 are vulnerable to BEAST and POODLE attacks.
5	Which is secure?	TLS v2.0 is susceptible to both BEAST & POODLE attacks and hence it is more secure.	The SSL versions are less secure.
6	When to choose TLS and when to choose SSL?	When your server is capable of running the latest version of TLS, then go ahead with this protocol. Otherwise, it is better to use SSL v3.0.	When the server is not capable of running TLS 1.2, go ahead with SSL v3.0 or any other versions of it.
7	Certificates	The server that is configured with TLS protocols uses TLS certificates of the respective version. For example, if the server is configured with TLS v1.0, then it uses the respective TLS v1.0 certificate.	The server that is configured with SSL protocols uses SSL certificates of the respective version. For example, if the server is configured with SSL v3.0, then it uses the respective SSL v3.0 certificate.
8	Are they compatible?	TLS is not compatible with versions of SSL.	Similarly, we can say it in the reverse.
9	Does IETF have deprecated the use of it?	No, there is no such deprecation associated with TLS versions.	Yes, it has deprecated the SSL v2.0 & v3.0.
10	When do you encounter certificate issues?	If you have configured your server with TLS protocols and if the communicating server uses any other certificate, this problem occurs.	If you have configured your server with SSL protocols and if the communicating server uses any other certificate, this problem occurs.
11	How to handle certificate issues?	Just disable the TLS configuration and configure your server with the other supporting protocols. But you should be cautious that such an act may create security issues and therefore, be sure to choose a secured internet protocol. Or else, simply ignore the communication with that particular server that does not support your TLS protocols.	You can disable the SSL server configuration as mentioned above.
12	Which is faster?	It is little slower due to the two-step communication process i.e. handshaking and actual data transfer.	It is faster than TLS as authentications are not carried out intensively.
13	Which is complex to manage on the server side?	It is complex as it requires certificate validations and good authentications.	It is simpler than the TLS as it lacks few features that are present in the TLS.
14	Back-compatibility	It is backward compatible and supports SSL.	It does not support TLS.

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