A widespread implementation of such ciphers is called a Feistel network, named after Horst Feistel, and notably implemented in the DES cipher.

For example, Triple DES has a key size of 168 bits but provides at most 112 bits of security, since an attack of complexity 2 < sup > 112 </ sup > is known.

This property of Triple DES is not a weakness provided 112 bits of security is sufficient for an application.

The Data Encryption Standard ( DES, or ) is a previously predominant algorithm for the encryption of electronic data.

This is chiefly due to the 56-bit key size being too small ; in January, 1999, distributed. net and the Electronic Frontier Foundation collaborated to publicly break a DES key in 22 hours and 15 minutes ( see chronology ).

The algorithm is believed to be practically secure in the form of Triple DES, although there are theoretical attacks.

The introduction of DES is considered to have been a catalyst for the academic study of cryptography, particularly of methods to crack block ciphers.

A generation of cryptanalysts has cut its teeth analyzing ( that is trying to " crack ") the DES algorithm.

" An astonishing share of the open literature in cryptography in the 1970s and 1980s dealt with the DES, and the DES is the standard against which every symmetric key algorithm since has been compared.

The discovery of differential cryptanalysis is generally attributed to Eli Biham and Adi Shamir in the late 1980s, who published a number of attacks against various block ciphers and hash functions, including a theoretical weakness in the Data Encryption Standard ( DES ).

It was noted by Biham and Shamir that DES is surprisingly resistant to differential cryptanalysis, in the sense that even small modifications to the algorithm would make it much more susceptible.

This is equivalent to around 70 bits, making it much stronger than the DES method which uses a 56 bit key.

The DES is a simple, quick, and validated questionnaire that has been widely used to screen for dissociative symptoms, with variations for children and adolescents.

He sponsored the EFF's Deep Crack DES cracker, the Micropolis city building game based on SimCity, and he is a proponent of opportunistic encryption.

For more sophisticated simulations Discrete Event Simulation ( DES ) is used with the advantages to simulate dynamics in the production system.

In cryptography, Triple DES is the common name for the Triple Data Encryption Algorithm ( TDEA or Triple DEA ) block cipher, which applies the Data Encryption Standard ( DES ) cipher algorithm three times to each data block.

This option is stronger than simply DES encrypting twice, e. g. with K < sub > 1 </ sub > and K < sub > 2 </ sub >, because it protects against meet-in-the-middle attacks.

Keying option 3 is equivalent to DES, with only 56 key bits.

In general, Triple DES with three independent keys ( keying option 1 ) has a key length of 168 bits ( three 56-bit DES keys ), but due to the meet-in-the-middle attack, the effective security it provides is only 112 bits.

The attack on DES is not generally practical, requiring 2 < sup > 43 </ sup > known plaintexts.

The publication of the DES cipher by the U. S. National Bureau of Standards ( now National Institute of Standards and Technology, NIST ) in 1977 was fundamental in the public understanding of modern block cipher design.

* Data Encryption Standard ( DES, now obsolete )

Its intended niche as a DES replacement has now mostly been filled by AES.

DES was originally considered effective and safe for both the pregnant woman and the developing baby.

As a consequence of this evidence, DES is considered an established human carcinogen.

These weak and semiweak keys are not considered " fatal flaws " of DES.

These are to be fed at a rate to provide 10 milligrams DES per head daily.

However, by the late 90s, it became clear that DES could be cracked in a few days ' time-frame with custom-built hardware such as could be purchased by a large corporation.

Another theoretical attack, linear cryptanalysis, was published in 1994, but it was a brute force attack in 1998 that demonstrated that DES could be attacked very practically, and highlighted the need for a replacement algorithm.

: The DES can be said to have " jump started " the nonmilitary study and development of encryption algorithms.

It can be used to attack symmetric ciphers such as Triple DES and AES by attempting to guess the secret key.

Tests such as the DES provide a quick method of screening subjects so that the more time-consuming structured clinical interview can be used in the group with high DES scores.

Type 2 products may not be used for classified information, but contain classified NSA algorithms ( e. g. CORDOBA ) that distinguish them from products containing unclassified algorithms like DES.

For example, 64-bit block ciphers like DES can be used to generate a keystream in output feedback ( OFB ) mode.

On January 2, 1997, NIST announced that they wished to choose a successor to DES to be known as AES.

Like DES, this was to be " an unclassified, publicly disclosed encryption algorithm capable of protecting sensitive government information well into the next century.

Elizabeth Kloepfer, Ann Rule, a DES employee, and a UW psychology professor all recognized the profile, the sketch, and the car, and reported Ted Bundy as a possible suspect ; but detectives, who were receiving up to 200 tips per day, initially thought it unlikely that a clean-cut law student with no adult criminal record could be the perpetrator.

Slightly more complex is the original DES method, which is to add a single one bit, followed by enough zero bits to fill out the block ; if the message ends on a block boundary, a whole padding block will be added.

It can be run against various encrypted password formats including several crypt password hash types most commonly found on various Unix flavors ( based on DES, MD5, or Blowfish ), Kerberos AFS, and Windows NT / 2000 / XP / 2003 LM hash.

In treating In-stent restenosis ( ISR ) Drug Eluting stents ( DES ) have been found to be superior to Intracoronary Brachytherapy ( ICBT ).

In 1941, Charles Huggins and Clarence Hodges at the University of Chicago found DES to be the first effective drug for treatment of metastatic prostate cancer.

Despite an absence of evidence supporting the use of DES to prevent adverse pregnancy outcomes, DES continued to be given to pregnant women through the 1960s.

The number of persons exposed to DES during pregnancy or in utero during 1940 – 1971 is unknown, but may be as high as 2 million in the United States.

In 1960, DES was found to be more effective than androgens in the treatment of advanced breast cancer in postmenopausal women.

To discourage off-label use of DES as a postcoital contraceptive, the FDA in 1975 removed DES 25 mg tablets from the market and ordered the labeling of lower doses ( 5 mg and lower ) of DES still approved for other indications changed to state: " This drug product should not be used as a postcoital contraceptive " in block capital letters on the first line of the physician prescribing information package insert and in a prominent and conspicuous location of the container and carton label.