Differences Between OpenVPN, PPTP, L2TP, SSTP, & IKEv2

With Edward Snowden’s surprising discoveries that the NSA has for years been working to split as well as suppress VPN encryption modern technologies, along with the fact that it is coming to be significantly evident that many such innovations have been established and approved by the US federal government’s National Institute of Standards and also Technology (NIST) and also could consequently be thought about suspect, we have determined it is time to revisit and also upgrade this prominent short article.

We will begin with a rundown of the major distinctions between the different VPN methods and just how they influence you, prior to looking in more specific at the vital principles engaged in cryptography, and also just how the NSA’s attack on encryption standards affects VPN users.

The discussion below is rather technological, as well as although I have made every effort making it as approachable as feasible, you could choose to just jump to the end of the article for a fast summary.



Point-to-Point Tunneling Protocol was established by a consortium established by Microsoft for creating VPN over dialup networks, and also because of this has long been the basic protocol for interior business VPN. It is a VPN protocol just, as well as counts on various verification methods to provide safety and security (with MS-CHAP v2 being one of the most common). Available as conventional on almost every VPN qualified system and device, and hence being simple to establish up without the should install additional software application, it stays a preferred selection both for companies as well as VPN providers. It likewise has the benefit of requiring a reduced computational overhead to execute (i.e. it’s quick).

Nonetheless, although currently generally just found making use of 128-bit encryption secrets, in the years considering that it wasted initially packed with Windows 95 OSR2 back in 1999, a variety of protection vulnerabilities have actually emerged, one of the most major which is the possibility of unencapsulated MS-CHAP v2 Authentication. Utilizing this make use of, PPTP has actually been split within 2 days, and although Microsoft has actually patched the problem (with using PEAP authentication), it has itself issued a referral that VPN users ought to use L2TP/IPsec or SSTP instead.

Recognizing that PPTP was apprehensive anyway, it came as no shock to any person that the NSA probably decrypts PPTP encrypted interactions as requirement. Possibly a lot more stressing is that the NSA has (or remains in the procedure of) probably decrypted the large quantities of older data it has actually stored, which was encrypted back when even protection professionals thought about PPTP to be secure.


  • Customer built-in to nearly all systems
  • Very simple to establish up
  • Really Fast


  • Never safe (the susceptible MS CHAPv2 authentication is still one of the most common in operation).
  • Absolutely jeopardized by the NSA.

L2TP as well as L2TP/IPsec.

Level 2 Tunnel Protocol is a VPN method that on its very own does not supply any kind of encryption or discretion to website traffic that passes with it. Therefore it is usually carried out with the IPsec encryption collection (just like a cipher, as discussed here) to provide protection as well as personal privacy.

L2TP/IPsec is built-in to all modern os and VPN qualified gadgets, and also is simply as easy and quick to establish as PPTP (actually it usually utilizes the very same customer). Issues can occur however, considering that the L2TP method makes use of UDP port 500, which is more quickly blocked by NAT firewall programs, as well as might for that reason call for sophisticated arrangement (port forwarding) when utilized behind a firewall program (this is unlike SSL which could make use of TCP port 443 making it identical from typical HTTPS website traffic).

IPsec encryption has no major recognized vulnerabilities, and also if correctly carried out may still be safe. Nonetheless, Edward Snowden’s revelations have highly hinted at the criterion being compromised by the NSA, and as John Gilmore (security professional as well as starting member of the Electronic Frontier Foundation) discusses in this post, it is most likely that it has actually been been purposely deteriorated during its style phase.

Relatively minor compared to the last point, but possibly worth discussing, is that due to the fact that L2TP/IPsec envelops data twice it is not as effective as SSL based options (such as OpenVPN as well as SSTP, and is for that reason slightly slower.


Generally considered very safe however see cons.
Easy to establish up.
Readily available on all modern platforms Cons.


May be jeopardized by the NSA.
Likely deliberately deteriorated by the NSA.
Slower compared to OpenVPN.
Can battle with limiting firewall softwares.


OpenVPN is a fairly new open resource innovation that utilizes the OpenSSL library and also SSLv3/TLSv1 protocols, along with an amalgam of various other technologies, to offer a trusted and also solid VPN solution. Among its major staminas is that it is very configurable, as well as although it runs best on a UDP port, it can be readied to work on any kind of port, consisting of TCP port 443. This makes website traffic on it impossible to differentiate from traffic using common HTTPS over SSL (as utilized by as an example Gmail), and also it is as a result very hard to block.

One more benefit of OpenVPN is that the OpenSSL library utilized to provide encryption sustains a number of cryptographic formulas (e.g. AES, Blowfish, 3DES, CAST-128, Camellia and more), although VPN providers practically specifically make use of either AES or Blowfish. 128-bit Blowfish is the default cipher constructed in to OpenVPN, as well as although it is typically considered secure, it does have known weak points, as well as its developer was quoted in 2007 as saying ‘at this moment, however, I’m impressed it’s still being used. If people ask, I suggest Twofish rather’.

AES is the more recent innovation, has no well-known weak points, as well as thanks to its fostering by the US government for usage in protecting ‘protected’ information, is generally taken into consideration the ‘gold criterion’ when it involves encryption. The reality that it has a 128-bit block dimension as opposed to Blowfish’s 64-bit block dimension also indicates that it can handle larger (over 1 GB) submits far better compared to Blowfish. However, both ciphers are NIST accredited, which while not commonly identified as issue, we have problems with. See listed below for a discussion about this.

How quick OpenVPN performs depends upon the level of encryption employed, but it is usually faster than IPsec.

OpenVPN has actually become the default VPN connection kind, and while natively sustained by no system, is widely sustained on the majority of with third celebration software program (including both iOS and Android).

As compared to PPTP and L2TP/IPsec, OpenVPN can be a piece fiddly to establish. When using common OpenVPN software specifically (such as the standard open resource OpenVPN customer for Windows), it is required to not just mount the customer and download, yet additionally to download and install and also arrangement added arrangement files. Many VPN suppliers get around this arrangement trouble by supplying personalized VPN customers.

Maybe most notably in light of the details acquired from Edward Snowden, it appears OpenVPN has not been endangered or weakened by the NSA, and is likewise (thanks to its consumption of ephemeral essential exchanges, as we will certainly go over later) unsusceptible NSA assaults on RSA vital encryption. Although no-one understands the complete capabilities of the NSA without a doubt, both the evidence and the maths highly direct to OpenVPN, if used together with a strong cipher, being the only VPN procedure that can be taken into consideration genuinely protected.



Highly configurable.
Quite safe and secure (most likely even against the NSA).
Could bypass firewalls.
Can use a large range of encryption formulas.
Open up resource (as well as can consequently be conveniently vetted for back entrances and also various other NSA design tampering).


Needs 3rd party software application.
Can be fiddly to establish.
Assistance on cell phones is boosting, but is not like on the desktop computer.


Safeguard Socket Tunneling Protocol was presented by Microsoft in Windows Vista SP1, and although it is now offered for Linux, RouterOS and also SEIL, it is still mainly a Windows-only platform (as well as there is a snowball’s opportunity in hell of it ever showing up on an Apple gadget!). SSTP makes use of SSL v3, and also consequently offers similar benefits to OpenVPN (such as the capability to utilize to TCP port 443 to prevent NAT firewall concerns), and also due to the fact that it is incorporated into Windows might be simpler to utilize and much more secure.

Unlike OpenVPN, SSTP is an exclusive standard possessed by Microsoft. This suggests that the code is not open to public examination, and also Microsoft’s history of co-operating with the NSA, and also on-going supposition regarding possible backdoors built-in to the Windows operating system, do not influence us with confidence in the specification.


Quite secure (depends on cipher, however typically really solid AES).
Entirely integrated right into Windows (Windows Vista SP1, Windows 7, Windows 8).
Microsoft support.
Could bypass most firewall programs.


Just truly operates in a Windows just setting.
Proprietary common possessed by Microsoft so can not be independently audited for back doorways as well as suchlike.


Net Key Exchange (version 2) is an IPSec based tunneling protocol that was collectively established by Microsoft and also Cisco, and which is baked into Windows variations 7 and above. The criterion is sustained by Blackberry devices, and independently created (and also suitable) open source applications are offered for Linux as well as various other operating systems. As always, we watch out for anything developed by Microsoft, however if open source variations are utilized then there need to be not a problem.

Called VPN Connect by Microsoft, IKEv2 is especially excellent at instantly re-establishing a VPN cable when individuals momentarily shed their net links (such as when going into or leaving a train tunnel).

Mobile individuals specifically, consequently, profit one of the most from utilizing IKEv2, which because of its support for the Mobility and also Multihoming (MOBIKE) method, additionally makes it extremely resistant to changing networks. This is great news for cell phone individuals who, as an example, attach their cell phones to a WiFi network while in your home however switch to mobile information use when out and also about, or that frequently switch between hotspots.

IKEv2 is also better to Blackberry individuals, as it is among minority VPN protocols supported by Blackberry tools.

It is not as common as IPSec (i.e. it is supported on much fewer platforms), but IKEv2 is considered at least like, if not above, L2TP/IPsec in regards to safety, efficiency (speed), and also security.


  • Faster than L2TP, sstp and pptp, as it does not entail the overhead connected with Point-to-Point procedures (PPP).
  • Extremely secure– especially when changing network or reconnecting after a lost internet line.
  • Quite safe and secure– assists AES 128, AES 192, AES 256 and also 3DES ciphers.
  • Easy to arrangement (a minimum of at the user-end!).
  • Protocol is sustained on Blackberry tools.


  • Not supported on many platforms.
  • Makes use of the very same UDP port 500 as IPSec (as well as PPTP), which is much easier to block compared to SSL based remedies such as OpenVPN or SSTP.
  • Executing IKEv2 at the server-end is challenging, which is something that might potentially cause concerns creating.
    We only rely on open source implementations.

Potential Problems from encryptions.

In order to understand encryption there are a number of crucial ideas that have to be grasped.

Encryption Key Stregnth

Secret length is the crudest means of determining how long a cipher will certainly require to crack, as it is the raw variety of ones as well as zeros used in a cipher. In a similar way, the crudest type of strike on a cipher is called a strength attack (or exhaustive essential search), which entails attempting every possible combination up until the right one is discovered.

Encryption made use of by VPN companies is invariably in between 256-bits and also 128-bits in key length (with greater degrees utilized for handshake and also data authentication), however what does this mean, and is 256-bit encryption truly more safe compared to 128-bit encryption?

Well to put these numbers right into viewpoint,.

  • A 128-bit essential cipher would need 3.4 x10(38) operations to accurately break.
  • In 2011 the fastest supercomputer in the word (the Fujitsu K computer located in Kobe, Japan) can an Rmax peak speed of 10.51 petaflops. Based upon this figure, it would take Fujitsu K 1.02 x 10(18) (around 1 billion) years to split a 128-bit AES key by pressure.
  • In 2013 one of the most powerful supercomputer on the planet is the NUDT Tianhe-2 in Guangzhou, China. Nearly 3 times as rapid as the Fujitsu K at 33.86 petaflops, it would certainly ‘just’ take it around a 3rd of a billion years to fracture a 128-bit AES key. That’s still a long period of time, as well as is the number for destroying merely one secret.
  • A 256-bit secret would call for 2(128) times even more computational power to break compared to a 128-bit one.
    The variety of operations required to strength a 256-bit cipher is 3.31 x 10(65), approximately equivalent to the number of atoms in deep space!

Up until the recent Edward Snowden discoveries, it was normally presumed that 128-bit encryption was in method uncrackable with brute pressure, and would be so one more for an additional century or so (taking Moore’s Law into account). Theoretically this still are true, however the sheer scale of sources that the NSA appears to have thrown at breaking encryption has actually trembled many experts’ faith in these predictions, as well as system supervisors all over the world are scrambling to upgrade cipher crucial lengths.

It should be kept in mind that the United States government makes use of 256-bit encryption to shield ‘sensitive’ information (and also 128-bit for ‘regular’ encryption needs). The approach it utilizes is AES, which as we will review here is not without problems.


While encryption key length describes the amount of raw of numbers included, ciphers are the maths utilized to carry out the encryption, and also it is weaknesses in these algorithms, as opposed to in the essential length, that often brings about encryption being destroyed.

Without a doubt one of the most typical ciphers that you will likely experience with VPN are Blowfish as well as AES. Along with this, RSA is utilized to secure and decrypt a cipher’s tricks, and SHA-1 or SHA-2 are made use of as a hash feature to validate the data.

AES is now usually taken into consideration one of the most secure cipher for VPN consumption, and its fostering by the United States government has actually only increased its perceived integrity, and also subsequently its appeal. There is reason to think this count on could be lost.


AES, RSA, sha-2 and also sha-1 were all created and/or accredited by the United States National Institute of Standards as well as Technology (NIST), a physical body that by its own admission functions carefully with the NSA in the development of its ciphers. Provided exactly what we now know of the NSA’s methodical initiatives to weaken or constructed back entrances right into international encryption requirements, there is every factor to question the honesty of NIST algorithms.

Although NIST has been fast to reject any incorrect doing (‘NIST would certainly not purposely weaken a cryptographic standard’), as well as has actually invited public engagement in a number of upcoming proposed encryption related specifications in an action developed to reinforce public self-confidence, the New York Times has accused the NSA of preventing the NIST accepted encryption specifications by either introducing undetectable backdoors, or suppressing the public development procedure to weaken the formulas.

This question was more boosted on September 17 2013, when RSA Security (a department of EMC) privately informed clients to stop using an encryption formula that reportedly consists of a flaw crafted by the National Security Agency.

Dual_EC_DRBG (Dual Elliptic Curve Deterministic Random Bit Generator) is an encryption typical crafted by NIST, as well as one that has been understood to be apprehensive for years, with the Eindhoven University of Technology in the Netherlands noting in 2006 that a strike versus it was simple sufficient to launch on ‘a regular COMPUTER’, as well as Microsoft designers flagging up a presumed backdoor in the formula. Despite these problems however, where NIST leads, industry will certainly adhere to, and also Microsoft, Cisco, Symantec and RSA all consist of the algorithm in their product’s cryptographic libraries, in huge part due the reality that conformity with NIST criteria is a prerequisite to getting US federal government contracts.

When you consider that NIST certified cryptographic requirements are basically ubiquitous globally throughout all locations of industry as well as company that depend on personal privacy (including the VPN market), this is all rather chilling. Maybe exactly since a lot counts on these specifications, cryptography experts have been reluctant to encounter up to the issue– at the very least up until Silent Circle, the firm which shut its Silent Mail service instead of see it compromised by the NSA, revealed in November 2013 that it intended to relocate away from NIST criteria.

Innovative VPN supplier LiquidVPN has actually likewise begun to experiment with non-NIST ciphers (as well as is presently utilizing Camellia CBC on its Russia server), yet this is the only VPN firm we are currently mindful of to reveal any sort of signs of relocating this instructions. Most VPN individuals will certainly as a result need to make do with 256-bit AES as the finest encryption typical presently readily available, yet we really hope that this will transform in the future.

NSA assaults on RSA crucial encryption.

Among the revelations that appeared of the brand-new details offered by Edward Snowden in September is that, “one more program, codenamed Cheesy Name, was focuseded on distinguishing encryption secrets, referred to as ‘certificates’, that might be vulnerable to being split by GCHQ supercomputers.”.

That these certifications can be ‘singled out’ highly suggests that 1024-bit RSA encryption (commonly utilized to shield the certificate tricks) is weak compared to formerly assumed, and can be decrypted far more quickly compared to anticipated by the NSA as well as GHCQ. Once a certification trick has been decrypted, then all exchanges past and also future will certainly be endangered if non ephemeral essential exchange is made use of (i.e. if, as is depressingly common practice, a solitary permanent personal trick is utilized to decrypt all data).

This indicates that lots of kinds of encryption which count on certificates and also non ephemeral secrets have to be pertained to damaged, consisting of SSL as well as TLS. This has significant ramifications for all HTTPS traffic.

The great news is that OpenVPN, which makes use of ephemeral (short-term) essential exchanges, must not be impacted. This is due to the fact that with ephemeral crucial exchanges a brand-new key is produced for each exchange, as well as there is therefore no dependence on certificates to develop count on. Even if a foe were to get the private secret of a certification, they can not decrypt the interaction. It is possible that a man between (MitM) assault could target an OpenVPN line if the exclusive secret has been comprised, but this would certainly need to be specifically targeted assault.

Since information that the NSA (as well as GHCQ) can split 1028-bit RSA encryption ended up being public, some VPN carriers at the very least have actually intensified their essential encryption to 2048-bits, or even approximately 4096-bits.

Perfect Forward Secrecy.

Another piece of good news is that solving this issue (even for SSL and also TLS lines) is simple if web sites carry out excellent onward privacy, a system wherein a one-of-a-kind and also new (without additional keys derived from it) personal encryption trick is produced for every session. (i.e. use of ephemeral crucial exchanges). However, as we go over in our write-up on the topic, the only major internet company to carry out PFS until now is Google (although this will ideally now start to transform).

Final thoughts.

Encryption works. Correctly applied solid crypto systems are among the couple of things that you could rely upon’, Edward Snowden.

Exactly what you must take away from this write-up is that OpenVPN stays a quite safe procedure, as well as that numerous VPN companies are functioning to reinforce their implementation of it. It would be excellent if service providers likewise started to relocate away NIST specifications, but also for that we will to wait as well as see.

  • PPTP is very unconfident (also its co-creator Microsoft has actually left it, and also it has been endangered by the NSA) as well as should for that reason be prevented. While its convenience of configuration and cross system compatibility are attractive, L2PT/IPsec has the very same benefits as well as is a lot more safe and secure.
  • L2TP/IPsec is a great VPN solution for non-critical usage, although it has been drastically endangered/ weakened by the NSA. For a quick VPN arrangement without the requirement to mount extra software program it stays beneficial, particularly for mobile devices where OpenVPN assistance remains somewhat patchy.
  • OpenVPN is easily the best all rounded VPN option, in spite of requiring third party software on all systems. It is dependable, fast, as well as (most importantly) secure (even versus the NSA), although it usually needs a little bit a lot more establishing compared to the various other procedures.
  • – IKEv2 is additionally a great (quick and safe) method (if open resource executions are made use of), especially for mobile customers who might even like it to OpenVPN thanks to its improved ability to reconnect when a net connection is interrupted. For Blackberry individuals, it is rather considerably the only alternative readily available.
  • SSTP provides the majority of the advantages of OpenVPN however only in a Windows atmosphere. This does mean that it is much better incorporated into the OS, however it is improperly sustained by VPN service providers thanks to this limit. Its exclusive nature and also the truth that is was developed by Microsoft imply that we for one don’t trust it.
  • So basically, where feasible you ought to always pick OpenVPN (or potentially IKEv2 if the alternative is readily available, particularly for mobile phones). If you require a filthy and also fast option (such as for shielding your phone from casual offenders when connecting to public WiFi hotspot) then L2TP/IPsec will probably do, yet offered the raising accessibility of OpenVPN apps for mobile tools (specifically Android), we would certainly still favor to make use of OpenVPN.

Rob Boirun

Rob Boirun

Staring in the storage industry in 1999, I worked for a DVD Burning API company that provided the burning engine for iTunes and other burning software. Today my love for all types of storage is being displayed here.

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