Release the data on the public internet in an encrypted form. With the data, include a message openly admitting you're a time traveler. Include predictions of events that are relatively resistant to the butterfly effect and will have little effect on the time stream. For example, I would include a long list of future supernovae and other astrophysical phenomena. Such data would accelerate the field of astronomy a bit, but it wouldn't really affect life on Earth much. And it would prove that you're either a time traveler or someone with access to FTL travel technology. In your message, tell people the data is of vital importance to the future of humanity and that it will be needed in a crucial hour.
There will be enough people who preserve a copy of the data and pass it along to their children and grandchildren. Forget relying on technical solutions. This is one you can rely on people for. Unless there's some complete collapse of technological society, the data will be preserved.