Security

Effective: November 24, 2014

Each person and each team using Slack expects their data to be secure, confidential, and private. We understand how important this is to our customers and work to the best of our abilities to ensure all three expectations are met. Please review the information below regarding our current policies and practices, along with our Privacy Policy and Terms of Service. This is a living document and we will update it as our service evolves and industry practices change.

As a company, we use the Slack service for nearly all of our communication. Ensuring that the Slack service remains secure is vital to protecting our own data. The security of your information is required for our success as a business. Below are some details on our security practices.

Encrypted Traffic by Default, in Both Directions

Slack uses 256-bit AES, supports TLS 1.2 for all of your messages, and uses the ECDHE_RSA Key Exchange Algorithm. We monitor the security community's output closely and work promptly to upgrade the service to respond to new vulnerabilities as they are discovered.

External Security Audits

We contract with respected, external security firms who perform regular audits of Slack to verify that our security practices are sound and to monitor the service in light of new vulnerabilities discovered by the security research community.

Secure Physical Location

Our servers are located in Amazon's AWS data centers. They've devoted an entire portion of their site to explaining their security measures, which you can find here: https://aws.amazon.com/compliance/

Experienced Team

Even before Slack, we've been putting services on the internet for a long time. We're good at it. Our engineering, quality assurance and technical operations team members are experienced and keep their skills up to date as industry best practices evolve. We’ve coded, tested and administered services running on thousands of physical servers in data centers around the world and we bring the collective wisdom that comes with many decades of secure practice to the operation of the Slack service.

Security Features for Team Members & Administrators

The highest security risk to any system is usually the behavior of its users. We want to provide you with the tools you need to protect your own data. For example, we log every time your account is signed in to, noting the device used and location of the connection, and make these access logs available to you.

Team Administrators can review consolidated access logs for the whole team. We also make it easy for each user to remotely close all Slack connections and sign out all devices authenticated with their Slack credentials at any time (so if you or one of your teammates lose your phone or laptop, you don't have as much to worry about).

We will continue to roll out additional features which afford you more control over the security of your own Slack team. We will also be adding more options for team administrators to set internal security policies, such as establishing password strength requirements or requiring use of PIN-lock functionality for Slack’s mobile apps.

Availability

We understand that you rely on Slack to work. We're committed to making Slack a highly-available, ultra-reliable service that you can always count on. We build systems that tolerate the failure of individual computers or whole datacenters, keep many copies of your data online for redundancy, practice disaster-recovery measures often, and always have staff on-call to quickly resolve unexpected incidents.

Confidentiality

We regard the information you share within your Slack team as private and confidential to your team. We place strict controls over our employees’ access to internal data and are committed to ensuring that your data is never seen by anyone who should not see it.

While the operation of the Slack service would not be possible unless there were some technical employees with sufficient system permissions to enable them to access and control software that stores and indexes the content you add to your Slack team, this team is kept purposefully small and are prohibited from using these permissions to view customer data unless it is necessary to do so.

All of our employees and contractors are bound to our policies regarding customer data and we treat these issues as matters of the highest importance within our company. If, in order to diagnose a problem you are having with the service, we would need to do something that would expose your personal communications to one of our employees in a readable form, we will ask for your consent prior to taking action. Our platform will automatically generate an audit entry of any such access.

There are limited circumstances when we ever share customer content without first obtaining permission. These are outlined in our Privacy Policy.

Privacy

A fundamental privacy principle we abide by is that by default, anything you post to Slack is private to your team. That is, viewing the messages and files shared within a specific team requires authentication as a member of that team. Slack has a comprehensive Privacy Policy that lays out our approach to privacy. Please take a moment to read it. Also please read our FAQs learn more about topics such as:

how permissions vary for communications that take place via team channels, private groups, and direct messaging,
the limited circumstances where content could be shared outside of of your team via Slack public links, and
different data retention policies that team owners and administrators might apply to message content.

If you are using Slack in a workplace or on a device or account issued to you by your employer or another organization, they will almost certainly have their own policies in place regarding storage, access, modification, deletion and retention of communications and content. Please check with your employer or team administrator about what policies they have in place regarding your communications and related content.

We know how important these issues are to you. They are equally important to us. The security, privacy and confidentiality of your information are core to our success as a business and we will continue to be proactive, vigilant and diligent in ensuring its safety.

If you have additional questions regarding data privacy, security or confidentiality, we’d be happy to answer them. Please write to feedback@slack.com and we’ll respond as quickly as we can.

If you believe you have found a security vulnerability on Slack, we encourage you to let us know right away. We will investigate all legitimate reports and do our best to quickly fix the problem. See our guidelines on Reporting Security Vulnerabilities.