WORM

from Wikipedia, the free encyclopedia

WORM refers to precautions in information technology that permanently exclude the deletion, overwriting and modification of data on a storage medium. The data memories used can only be read and continued to be written to up to their capacity limit. The name is an acronym for “ write once read many ” or “ write once read multiple ” ( English for “write once, read many”).

History and variants

The term WORM was mainly used in connection with optical storage media and tape drives . As a result of further developments, the term now refers to all storage media that store the information in a way that cannot be changed or deleted.

In a broader sense, WORM also appears in connection with archiving programs which, due to the type of formatting, make the connected medium writable once.

All solutions for temporary write protection or encryption do not fall under WORM .

A distinction must be made in the narrower sense: Hardware WORM and systemic WORM. While the WORM property is irreversibly created in the storage medium by physical changes in the former, the protection against erasure in the latter arises from the interaction between the storage processor / controller and the storage medium. In the further version, Software WORM can be added as a third category.

Hardware WORM

From hardware WORM (also: TrueWORM called) is when the write-once property is given physically. In this case, either depressions or bubbles are created inside the medium by a laser beam . These cannot be changed again at a later point in time.

Unlike a rewritable CD ( CD-RW ), a WORM data storage device such as a CD-R does not allow data to be erased. Originally, the term WORM referred to very specific media and drives . These media are in a protective cover and were initially available in 14 ", 12", 8 ", 5¼" and 3½ "diameters. In 2006, only the media with 5¼" diameter will play a role. Most modern TrueWORMs in UDO or PDD technology have been used in electronic archive systems since 2006 .

TrueWORM systems based on rotating media have the problem of low storage space, a current UDO 2 medium only holds 60 GB, while archiving systems with software WORM are also available in the TB area.

Systemic WORM

With the systemic WORM , the one-time writability is achieved either through addressing or management by the internal processor / controller.

In the form of a WORM USB stick, the SECUMEM memory, for example, defines the one-time writability by the internal controller of the USB stick.

Even MO drives are available with WORM properties.

Content-Addressed Storage (CAS) is a technology that creates the write-once property on the software side. CAS is mostly sold as a dedicated hard drive system. Examples of this are the Centera from EMC, Caringo, and Silent Cubes.

Software WORM

WORM can also be the pure software functionality in a network storage system, such as that offered by iTernity with iCAS, SER with SafeLock, NetApp with SnapLock or Grau Data GmbH with FileLock. In this case one speaks of software WORM (also called: SoftWORM).

WORM is also possible on special magnetic tapes (WORM tape) with appropriate drives. If hard disk drives are used, the term WORM raid is often used .

A special form of WORM sealing is used by systems from FAST LTA . As with SoftWORM, commercially available hard drives are used as media, the WORM functionality is ensured by an external hard drive controller. This controller distributes the data evenly to the connected hard drives and writes the data in a purely linear manner. This controller does not recognize commands for deleting or overwriting. Since the special file system is also firmly anchored in the controller, the hard disks cannot be manipulated by connecting them to other hard disk or RAID controllers.

Application and security

In the age of server-based storage, memories such as CD-R have become out of fashion as data carriers.

A major application of WORM media, on the other hand, is digital archiving. These are used for large quantities of unchangeable documents and receipts. They are becoming increasingly important again since the legislature, which allows financial management and compliance regulations to store digital documents in an unchangeable manner, or even prescribe them. The GDPdU is particularly important here. But regulations such as SOX, Basel II and others also rely on the unchangeability of the stored documents.

When using all WORM systems, however, it must be noted that only one overall solution including document management and secure operation can meet the legal requirements. The use of WORM media alone is not sufficient. As a rule, content and saved data can be easily manipulated before saving. This can be remedied by integrating it into comprehensive archiving systems and data carriers with their own timer and usage monitoring such as B. the SECUMEM memory.

In particular with software WORM, but also with systemic WORM, the immutability cannot be fully proven. Security gaps in software or hardware caused by programming errors could be exploited to bypass the overwrite protection.

See also

swell

Individual evidence

  1. ^ WORM Technology. Hewlett-Packard , IBM , Quantum , archived from the original on July 27, 2011 ; Retrieved June 6, 2011 .
  2. ^ Why the Future of Compliant Archiving Will Be Software-Defined. In: community.hpe.com. September 20, 2017, accessed September 27, 2019 .
  3. ↑ Simply audit-proof. September 18, 2014, accessed January 16, 2019 .
  4. ↑ Christoph Lange: Software solution for revision security. LANline , December 15, 2012, accessed February 6, 2014 .