SanDisk has now announced a one gigabyte Secure Digital card that can store data for 100 years, but can be written on only once. Secure Digital cards are used in many digital cameras as well as other devices. The WORM (write once, read many) card is "tamper-proof" and data cannot be altered or deleted, SanDisk said in a statement. The card is designed for long-time preservation of crucial data like legal documents, medical files and forensic evidence, SanDisk said.
SanDisk determined the media's 100-year data-retention lifespan based on internal tests conducted at normal room temperatures. The company said it is shipping the media in volume to the Japanese police force to archive images as an alternative to film. The company is working with a number of consumer electronics companies, including camera vendors, to support the media.
You can read more at http://www.computerworld.com/s/article/9178428/SanDisk_s_SD_card_can_store_data_for_100_years
Now the big question is: Will computers be able to read SD cards 100 years from now? I doubt it. Regardless of the life expectancy of these new cards, the information still needs to be copied to more modern media every few years in order to guarantee availability 100 years from now.