SanDisk has recently unveiled a unique SD card called the WORM card, which is short for Write Once Read Many. Its name summarizes what the SD card can do in that single phrase: that is to store data which cannot be altered and hence prevents data tampering.
This makes the SanDisk SD WORM Card perfect for police investigations, electronic voting, medical devices, recorders for security cameras, cash registers, and court testimonies; processes wherein which unalterable memory storage devices are preferred. The device can last 100 years if stored properly which is probably the closest thing to eternal data you can get. The available SanDisk SD WORM card has a 128MB capacity for now, although higher capacities will be available in the near future.