Accelerate your SSE journey. Join Netskope at RSA.

  • Security Service Edge Products

    Protect against advanced and cloud-enabled threats and safeguard data across all vectors.

  • Borderless SD-WAN

    Confidently provide secure, high-performance access to every remote user, device, site, and cloud.

  • Platform

    Unrivaled visibility and real-time data and threat protection on the world's largest security private cloud.

Netskope Named a Leader in the 2022 Gartner Magic Quadrant™ for SSE Report

Get the report Go to Products Overview
Netskope gartner mq 2022 sse leader
Gartner® Quick Answer: How Does Netskope’s Acquisition of Infiot Impact SD-WAN, SASE, and SSE Projects?

Get the report
Gartner quick answer
Netskope delivers a modern cloud security stack, with unified capabilities for data and threat protection, plus secure private access.

Explore our platform
Birds eye view metropolitan city
Make the move to market-leading cloud security services with minimal latency and high reliability.

Learn more
Lighted highway through mountainside switchbacks
Prevent threats that often evade other security solutions using a single-pass SSE framework.

Learn more
Lighting storm over metropolitan area
Zero trust solutions for SSE and SASE deployments

Learn more
Boat driving through open sea
Netskope enables a safe, cloud-smart, and fast journey to adopt cloud services, apps, and public cloud infrastructure.

Learn more
Wind turbines along cliffside
  • Our Customers

    Netskope serves more than 2,000 customers worldwide including more than 25 of the Fortune 100

  • Customer Solutions

    We are here for you and with you every step of the way, ensuring your success with Netskope.

  • Training and Certification

    Netskope training will help you become a cloud security expert.

We help our customers to be Ready for Anything

See our Customers
Woman smiling with glasses looking out window
Netskope’s talented and experienced Professional Services team provides a prescriptive approach to your successful implementation.

Learn more
Netskope Professional Services
Secure your digital transformation journey and make the most of your cloud, web, and private applications with Netskope training.

Learn more
Group of young professionals working
  • Resources

    Learn more about how Netskope can help you secure your journey to the cloud.

  • Blog

    Learn how Netskope enables security and networking transformation through security service edge (SSE).

  • Events & Workshops

    Stay ahead of the latest security trends and connect with your peers.

  • Security Defined

    Everything you need to know in our cybersecurity encyclopedia.

Security Visionaries Podcast

Episode 10: Building Security Relationships Through Transparency
In this episode, Mike and Andreas discuss aligning with works councils, forging business relationships through transparency, and embedding security into value streams.

Play the podcast
Building Security Relationships Through Transparency
Read the latest on how Netskope can enable the Zero Trust and SASE journey through security service edge (SSE) capabilities.

Read the blog
Sunrise and cloudy sky
Netskope at RSA

Join Netskope at RSA Conference this year and be part of the real conversations on SASE and Zero Trust. Stop by our booth in South Hall, chat with an expert, register for our speaking sessions, and unwind by joining us at one of our events!

Learn more
RSA logo
What is Security Service Edge?

Explore the security side of SASE, the future of network and protection in the cloud.

Learn more
Four-way roundabout
  • Company

    We help you stay ahead of cloud, data, and network security challenges.

  • Why Netskope

    Cloud transformation and work from anywhere have changed how security needs to work.

  • Leadership

    Our leadership team is fiercely committed to doing everything it takes to make our customers successful.

  • Partners

    We partner with security leaders to help you secure your journey to the cloud.

Netskope enables the future of work.

Find out more
Curvy road through wooded area
Netskope is redefining cloud, data, and network security to help organizations apply Zero Trust principles to protect data.

Learn more
Switchback road atop a cliffside
Thinkers, builders, dreamers, innovators. Together, we deliver cutting-edge cloud security solutions to help our customers protect their data and people.

Meet our team
Group of hikers scaling a snowy mountain
Netskope’s partner-centric go-to-market strategy enables our partners to maximize their growth and profitability while transforming enterprise security.

Learn more
Group of diverse young professionals smiling

SASE and TLS 1.3, Part 2: Naming Names

Oct 13 2020

Recall from Part One that we identified three different places in a SASE product where TLS 1.3 support is relevant. In descending order of importance, those places are: proxy, tunnel, and management interface. We also identified three different ways that vendors “support” TLS 1.3: in descending order of quality, they were “true,” “down-negotiate,” or “bypass.” 

Surprisingly, despite the merits of TLS 1.3, and more than two years after it was finalized, some security vendors still don’t have true TLS 1.3 support in their proxy. Even more alarming, you can find people who say publicly (but incorrectly) that those vendors support TLS 1.3, which is only true in a weak, spinning-a-story, marketing-and-sales kind of way.

Now let’s talk about some well-known vendors and what they do.

VendorApproachConnects to strict TLS 1.3?Security with TLS 1.3?
NetskopeTrue TLS 1.3YesYes
ZscalerDown-negotiate or bypassBypassNo
Symantec WSSDown-negotiateNoNo

As we’ve already noted, Netskope has a true TLS 1.3 implementation for our proxy. We’ve counted at least six other security vendors who have chosen to do likewise, which is not very surprising. After all, this is the choice you would expect security vendors to make. What’s more surprising are the vendors who haven’t done a true TLS 1.3 implementation (at least, not yet). 

For example, Zscaler uses the combined “down-negotiate or bypass” strategy. That means Zscaler won’t necessarily break a would-be TLS 1.3 connection by making it impossible for client and server to communicate. But since Zscaler can’t actually deliver their security processing over a TLS 1.3 connection, their cloud has to decide on every new connection whether to give up on TLS 1.3 or give up on security processing. 

Every time a TLS 1.3 user tries to connect via Zscaler to a service that supports TLS 1.2, Zscaler will downgrade that connection. But every time such a user tries to connect to a service that requires TLS 1.3, Zscaler will completely bypass the connection and perform no security inspection on it. (Well, there’s an alternative: in this situation, Zscaler can also block the connection as undecryptable traffic. That choice still does no security processing, but might be preferable in some cases. Any way we look at it, it’s clearly not great that the only available choices here are “turn off security” or “disallow service.”)  

Symantec WSS appears to use only the down-negotiate strategy. Most servers support TLS 1.2 for compatibility, and so in the common case, Symantec WSS will behave similarly to Zscaler. It will lower the security and performance of the connection compared to what the client could have achieved on its own, but the client will still connect to the server and Symantec WSS will still perform its security processing. However, if the server refuses to negotiate TLS 1.2, Symantec WSS will actually prevent a TLS 1.3 client from connecting to a TLS 1.3 server. In that situation, Symantec WSS may actually impair enterprise productivity instead of enhancing enterprise security. 

Let’s also note that these vendors will almost certainly fix these problems eventually. Indeed, they might even have fixed them by the time you read this article. Will that make all of this discussion irrelevant? Not completely, because it’s still striking how long it’s taken them. We first discovered the weakness of some competitive implementations in early December 2019, when Netskope already supported TLS 1.3. It seemed all but certain that those other vendors would soon catch up… but it’s now October 2020. It started to look as though actually implementing TLS 1.3 wasn’t very important to some vendors. Instead, they could just “support” it in the ways described in Part One

Sources of information

How can you determine a vendor’s support for TLS 1.3? As this article (and Part One) have shown, it’s not as simple as just asking!

The best approach is to actually experiment with the product of interest. One easy test is to visit facebook.com via a proxy of interest using Firefox. You can then go to Tools>Page Info>Security to see the details of the browser’s connection on that page: 

  • What you want to see is a TLS 1.3 connection, secured by the proxy vendor’s certificate. That result means that the proxy is in the path and using TLS 1.3. 
  • If you see TLS 1.2, then the proxy has negotiated down. 
  • If you see a TLS 1.3 connection that is secured by Facebook’s certificate, then the proxy has bypassed.

The next-best alternative seems to be the vendor’s support sites, but some detective work may be involved. Both Zscaler and Symantec acknowledge the limitations of their TLS support, although only implicitly. Zscaler’s support site currently lists out supported protocols but omits TLS 1.3, while the Broadcom support site for Symantec WSS responds to a TLS 1.3 problem by explaining how to disable TLS 1.3 in the browser

How about a vendor’s corporate blog or a third-party site? At least for what we’ve seen, the information there seems noticeably lower in quality. For example, Zscaler’s corporate blog has a lengthy article about TLS 1.3 that never actually claims that Zscaler supports it, but certainly seems to imply it. When read carefully, there’s nothing actually incorrect about the article, but it also isn’t a model of straightforward communication.

Likewise, there’s a fascinating blog post by Brian Deitch from 2018 that claims Zscaler has this all taken care of, which is incorrect. The post mostly complains about legacy box vendors and makes some good points. But since it’s now 2020 and Zscaler still doesn’t support TLS 1.3, clearly there was a bug somewhere in the author’s assessment. 

Symantec’s corporate blog similarly has a post on DoH that mentions using a TLS 1.3 proxy for additional control without clearly stating that Symantec WSS doesn’t operate as such a proxy. Again, if you read the article very carefully, it’s not actually untruthful… it just doesn’t help the reader understand the actual state of the world. 

Bottom line 

Part One was an introduction to the surprising complexities lurking in TLS 1.3 support, and we laid out a framework to understand what’s happening there with any SASE or would-be SASE vendor. As a reminder, part of what we tackled there was the “so what?” question about why TLS 1.3 support matters. In this article, we looked at some specific vendors. If you want to apply this same approach to other vendors, keep in mind:

  • TLS 1.3 matters for both security and performance. If you don’t know the details of what your vendor does when proxying TLS traffic, you may be opening yourself to unexpected vulnerabilities as well as sacrificing performance. 
  • TLS 1.3 “support” might not mean what you think; be aware of the alternative ways that a vendor may “support” the protocol.
  • Experimenting with the product, or carefully reading the vendor’s support site are two likely ways to clarify the situation.
  • Corporate blogs and third-party sites seem to be less reliable sources of information.
author image
Mark Day
Mark Day brings a diverse background to his role at Netskope, where he combines his interests in competitive analysis and technology strategy. He is author of the book Bits to Bitcoin: How Our Digital Stuff Works. He has more than thirty patented inventions, and has taught at both MIT and Harvard.