Details of Encryption

December 18th, 2006

Encryption is a method of protecting data by translating it into a secret code. Encrypted data is sometimes referred to as cypher text as opposed to unencrypted plaint text. To read an encrypted document, one must have either a key or password to decrypt it. There are two general categories of encrypted data: symmetrical and asymmetrical.

Asymmetrical Encryption is also called public-key encryption. This system uses a public key and a private key to encrypt data. The intended recipient of an encrypted message can provide his or her public key to the individual sending the message. The sender then uses the public key to encrypt the message. The private key is held only by the intended recipient. In essence, the public key is used to lock the data and the private key is used to unlock the data. It is impossible to decrypt the data without the private key. Pretty Good Privacy (PGP) is a widely used encryption tool in the United States.

Like asymmetrical encryption, Symmetrical Encryption uses keys to encrypt and decrypt messages. However, rather than using two separate keys, the same key is used to encrypt and decypher the message.

Data Types

December 14th, 2006

Courts recognize five categories of data which are discoverable in Federal courts. The pivotal case, Zubulake v. UBS Warburg, LLC, 217 F.R.D. 309, enunciated these categories of data. The first three types of data are considered accessible by the courts, whereas the last two are considered inaccessible.

Active, Online data is usually stored on magnetic discs, such as hard drives. Active data is data that is presently in use or is accessed frequently. It is the simplest data to obtain.

Near-line data that is stored using a robotic storage device, which employs robotic arms to access media. Optical discs are one example of near-line data.

Offline storage/archives are data that is stored in a removable form of media, such as a removable optical disc or magnetic tape, that can be stored on a shelf outside of the computer. Frequently, offline storage is used to make disaster copies or to store data that is not accessed often.

Backup tapes are devices that record data and write it onto tapes. Backup tapes have significant storage capacity of up to several gigabytes. Data is not organized by file, making recovery of documents from back up tapes both time-consuming and expensive.

When data is saved to a computer, it is stored in contiguous clusters. As each file is erased, those clusters become open space. As the remaining files grow, they can expand beyond the contiguous space available on the hard drive. When the files outgrow the space, they are broken up, or fragmented, and the fragments are placed randomly throughout the hard drive. Fragmented, erased or damaged data can only be accessed using computer forensics. Erased data is not truly deleted from the hard drive until the computer writes over the erased data.

For more definitions, please visit our Glossary of Terms page.

Bytes, Kilobytes and Gigabytes, OH MY!

December 11th, 2006

The smallest unit of information on a computer is a bit, which is short for the term binary digit and can only consist of the numbers 0 or 1. Bits are used in various combinations of the numbers 0 and 1 to create meaningful information, such as a byte.

byte is a computer storage unit containing enough memory to hold a store a single character, such as a number or a letter. It is composed of eight bits.

Because bytes are a small unit, it is more common to see the terms kilobytes and gigabytes to refer to storage space on a computer.

Kilobyte: 1,024 bytes

Megabyte: 1,048,576 bytes or 1,024 kilobytes

Gigabyte: 1,073,741,824 bytes or 1,024 megabytes

It can be difficult to conceptualize the amount of electronic data contained in a byte.  Different documents take up varying amounts of space.

The following examples demonstrate the approximate quantities of data that can be stored in a single gigabyte of space:

Microsoft Word files: 65,000 pages

E-mail files: 100,000 files

Text files: 675,000 pages

For more definitions, please visit our Glossary of Terms page.

Nuts & Bolts of Electronic Data

December 4th, 2006

Electronic data is everywhere. We create data each time we send an e-mail; swipe a credit card; or drive down the street. The following statistics demonstrate the pervasive nature of electronic data and its swift expansion in recent times:

According to a University of California study, 93% of all information generated in 1999 was generated in digital form, on computers. Only 7% of information originated in other media, such as paper. In re Bristol-Myers Squibb Securities Litigation, 205 F.R.D. 437, 440 n.2 (D.N.J. 2002).

Internet usage has grown 112% from 2000 to 2006 in North America, with approximately 69% of the population using the internet. (http://www.internetworldstats.com/ )

”75 percent of Americans use the Internet and spend an average three hours a day online.” Brad Stone, “Hi-Tech’s New Day”, Newsweek, April 11, 2005, p. 62.

For 2005, about 64 percent of new [car] models had black boxes, a figure that likely is much higher now. Toyota installs them in all of its vehicles, while GM and Ford equip nearly all their models. DaimlerChrysler AG’s Chrysler Group has the technology in more than half. David Shepardson, Black Boxes Spark Uproar, The Detroit News, October 30, 2006.