ephemeral sharing
pp. Sharing a photo, file, or other content electronically, but allowing the recipient to view it for only a limited time.
With consumer devices now an integral part of the workplace and use of file-sharing tools like Dropbox and Box increasing, enterprises are scrambling to protect their sensitive information. The idea of endowing files with a finite lifespan before they self-destruct is appealing, because it offers senders greater control over data as they share it externally.

Today, new applications are emerging that provide this type of ephemeral sharing capability. Unlike the digital rights management solutions of yore, these technologies are cloud-based, simple to use, and can be easily integrated into users’ workflows.
—Joe Moriarity, “The Snapchat Effect: Self-Detonating Data in the Enterprise,” Wired Innovation Insights, December 12, 2013
While photo documentation used to connote some level of importance, the ubiquitousness of Facebook and the popularity of documenting the mundane has created a situation where deciding not to document something tends to give it more meaning. As a result, the ephemeral sharing of a moment on Snapchat begins to release users from the tensions caused by "hyper documentation."
—Katharine Schwab, “Snapchat takes digital retro: free to be candid,” The San Francisco Chronicle, August 11, 2013
2007 (earliest)
The creation of direct contacts is intended for establishing long-lived sharing relationships between two users. When only ephemeral sharing is necessary, users may use the Passlet mechanism to allow access, without creating an entry to MyNetBook.
—Dimitris N. Kalofonos, “MyNetSec: Intuitive Security for Peer-to-Peer (P2P) Personal and Social Networking Services” (PDF), Nokia Research Center, November 06, 2007