With the introduction of Design Specs (Beta) for Adobe XD in November 2017, viewers of published Design Specs were required to sign-in with an Adobe ID.
To make accessing Design Specs more seamless, effective as of March 21, 2018, viewing a published Design Specs no longer requires a sign-in with an Adobe ID.
All existing Design Specs URLs remain the same and are still public links, meaning that anyone who has the link is able to view it. Any new Design Specs that you publish will also no longer require a sign-in with an Adobe ID.
The XD team is actively working on other ways to permit or deny access to these shared links. We will share an update regarding this as soon as it is ready.
If you wish to remove access to a Design Specs link, you can delete it from your list of existing Design Specs links, at https://assets.adobe.com/links. You can access this link by typing it in your browser, or from within Adobe XD, by selecting File > Manage Published Links.