Lock It Up And Throw Away The Key

I’m in Europe this week to talk to the press about data regulations and about our Decru acquisition, and also to visit customers. When I look at government regulations of data, they tend to fall into three very broad categories. Regulations about:

#1) Data that companies must keep

#2) Data that companies must keep secret (or private)

#3) Data that companies must delete

A banking transaction is an example of all three. If you deposit a check, the bank must keep a record of the transaction for seven years (10 years in Germany and Italy). The bank must keep the data private - unless the government wants to investigate your taxes or something. After seven years, the bank must delete the data.

It is obvious that encryption can help keep data secret. It is less obvious that encryption can help delete data. Consider the example of a company that makes weekly backup tapes and sends them offsite. After a few years, the record of your check deposit may be saved on hundreds of different tapes. How can you delete that data, after seven years, especially given that it sits on tape next to other data that must not yet be deleted?

Every encryption system has "keys" that are used to encrypt data, and to decrypt it later. The easiest way to delete data is to throw away the key. This works even if you have lots of copies on lots of tapes stored in multiple warehouses. The most common question I get about throwing away the keys is this: "Is the data really gone? Is it legally considered to have been deleted?" The answer is yes! That’s exactly what the Department of Defense’s DoD 5015.2 Certification means. If you throw away the key, you can legally consider the data to have been deleted, at least as far as the Department of Defense is concerned.