|Shredders range in size and price from small and inexpensive units meant for a few pages, to large units used by commercial shredding services that cost hundreds of thousands of dollars and can shred millions of documents an hour. Some shredders used by a commercial shredding service are built into a shredding truck.
The normal small shredder is an electrically powered device, but there are unpowered ones such as special scissors with multiple blade pair and shredders which are hand-cranked.
These machines are classified according to the size and shape of the shreds they produce. (As a practical matter, this is also a measure of the degree of randomness or entropy they generate.) Shredders can range in size from standard scissors and other hand-operated devices all the way up to truck-sized shredders. There are also shredder selector sites that can help consumers choose a shredder that is appropriate for their needs.
Strip-cut shredders, the least secure, use rotating knives to cut narrow strips as long as the original sheet of paper. Such strips can be reassembled by a determined and patient investigator or adversary, as the product (the destroyed information) of this type of shredder is the least randomized. It also creates the highest volume of waste inasmuch as the chad has the largest surface area and is not compressed.|