Unforgettable: SD WORM cards up to 1 GB
Source: SanDisk Storage media specialist SanDisk supplies unerasable SD cards with a capacity of 1 GB that offer a 100-year data preservation guarantee and provide revision security for auditing and forensic evidence purposes. The cards provide what is called WORM storage – "write once read many" – which only allows data to be added, but not edited or removed except by physically or electrically destroying the storage medium.
On the outside, SD WORMs look just like normal SD cards. However, the camera used must be WORM compatible; many professional camera models already support WORM cards. The card can be read with any card reader. The cards can also be used in audio recorders. Sandisk is currently supplying the Japanese police with large quantities; however, WORMs are considerably more expensive than SD cards with a similar capacity.