Password Authentication Protocol

Password Authentication Protocol (PAP) is a password-based authentication protocol used by Point-to-Point Protocol (PPP) to validate users.[1] PAP is specified in RFC 1334.

Almost all network operating systems support PPP with PAP, as do most network access servers. PAP is also used in PPPoE, for authenticating DSL users.

As the Point-to-Point Protocol (PPP) sends data unencrypted and "in the clear", PAP is vulnerable to any attacker who can observe the PPP session. An attacker can see the users name, password, and any other information associated with the PPP session. Some additional security can be gained on the PPP link by using CHAP or EAP. However, there are always tradeoffs when choosing an authentication method, and there is no single answer for which is more secure.

When PAP is used in PPP, it is considered a weak authentication scheme. Weak schemes are simpler and have lighter computational overhead than more complex schemes such as Transport Layer Security (TLS), but they are much more vulnerable to attack. While weak schemes are used where the transport layer is expected to be physically secure, such as a home DSL link. Where the transport layer is not physically secure a system such as Transport Layer Security (TLS) or Internet Protocol Security (IPsec) is used instead.

Other uses of PAP

PAP is also used to describe password authentication in other protocols such as RADIUS and Diameter. However, those protocols provide for transport or network layer security, and therefore that usage of PAP does not have the security issues seen when PAP is used with PPP.

Benefits of PAP

When the client sends a clear-text password, the authentication server will receive it, and compare it to a "known good" password. Since the authentication server has received the password in clear-text, the format of the stored password can be chosen to be secure "at rest". If an attacker were to steal the entire database of passwords, it is computationally infeasible to reverse the function to recover a plaintext password.

As a result, while PAP passwords are less secure when sent over a PPP link, they allow for more secure storage "at rest" than with other methods such as CHAP.

Working cycle

PAP authentication is only done at the time of the initial link establishment, and verifies the identity of the client using a two-way handshake.

  1. Client sends username and password. This is sent repeatedly until a response is received from the server.
  2. Server sends authentication-ack (if credentials are OK) or authentication-nak (otherwise)[2]

PAP packets

Description

1 byte 1 byte 2 bytes 1 byte Variable 1 byte Variable
Authentication-request Code = 1 ID Length Username length Username Password length Password
Authentication-ack Code = 2 ID Length Message length Message
Authentication-nak Code = 3 ID Length Message length Message

PAP packet embedded in a PPP frame. The protocol field has a value of C023 (hex).

Flag Address Control Protocol (C023 (hex)) Payload (table above) FCS Flag

See also

Notes

  1. ^ "Password Authentication Protocol (PAP)". GeeksforGeeks. 2018-07-17. Retrieved 2020-11-08.
  2. ^ Forouzan (2007). Data Commn & Networking 4E Sie. McGraw-Hill Education (India) Pvt Limited. pp. 352–. ISBN 978-0-07-063414-5. Retrieved 24 November 2012.

References

Read other articles:

Hajime Tsuburaya

Hajime TsuburayaTsuburaya pada tahun 1962Nama asal円谷 一Lahir28 April 1931[a]Tokyo, JepangMeninggal9 Februari 1973 (usia 41)Tokyo, JepangPekerjaanSutradara, produser penulis skenario, sinematografer, penulis lirik, presiden Tsuburaya ProductionsTahun aktif1954–1973Anak3, termasuk HiroshiOrang tuaEiji Tsuburaya (bapak)Masano Araki (ibu) Hajime Tsuburaya (Jepang: 円谷 一code: ja is deprecated , Hepburn: Tsuburaya Hajime, 28 April 1931 – 9 Februari 1973[1]) ...

 

Hidangan Arab Saudi

Salah satu contoh hidangan arab saudi Hidangan Arab Saudi dipengaruhi oleh beberapa hal, seperti iklim, sejarah, dan aturan negara Arab Saudi sendiri sebagai negara Islam. Dengan iklim gurunnya, Arab Saudi memiliki hidangan yang beraneka ragam dan rasa. Gaya hidup nomaden di masa lalu juga tercermin pada hidangan tradisionalnya, seperti rempah-rempah, beras basmati, kurma kering, dan jeruk limau hitam kering musky. Bahan-bahan tersebut tahan lama dan mudah dibawa dalam perjalanan jauh. Selain...

 

Gereja Kristen Anugerah

Gereja Kristen AnugerahLogo GKAPenggolonganPantekostaPemimpinBishop Prof. Dr. Jahja HardjojoDidirikan20 Juli 1968 Jakarta, DKI JakartaNama lainGKA Gereja Kristen Anugerah (disingkat GKA) tidak munculndengan sendirinya, melainkan merupakan hasil usaha pemberitaan Injil dilakukan oleh seorang hamba Tuhan bernama Bishop Prof. Dr. Jahja Hardjojo, yang menghasilkan suatu persekutuan orang-orang beriman kepada Yesus Kristus. Sejarah singkat GKA bermula dari penginjilan langsung ke rumah-rumah, mend...

Gene Makowsky

Canadian politician The HonourableGene MakowskyMLAMember of the Saskatchewan Legislative Assemblyfor Regina Gardiner ParkRegina Dewdney (2011-2016)IncumbentAssumed office November 7, 2011Preceded byKevin Yates Personal detailsBorn (1973-04-17) April 17, 1973 (age 50)Saskatoon, Saskatchewan, CanadaPolitical partySaskatchewan PartyResidenceRegina, SaskatchewanAlma materUniversity of SaskatchewanOccupationProfessional athleteFootball careerCareer informationStatusRetiredCFL statusN...

 

Conseil de défense et de sécurité nationale

Conseil de défense et de sécurité nationaleHistoireFondation 24 décembre 2009CadreZone d'activité FranceType Conseil des ministres restreintSiège ParisPays  FranceOrganisationSecrétaire général Secrétariat général de la Défense et de la Sécurité nationaleSite web www.elysee.fr/la-presidence/le-conseil-de-defense-et-de-securite-nationalemodifier - modifier le code - modifier Wikidata Le Conseil de défense et de sécurité nationale (CDSN) français est un Conseil des minis...

 

Darryl Braxton

Soap opera character Darryl BraxtonHome and Away characterPortrayed bySteve PeacockeDuration2011–2016First appearance16 February 2011Last appearance7 June 2016ClassificationFormer; regularIntroduced byCameron WelshBook appearancesHome and Away: New Beginnings[1]In-universe informationOccupationBusinessman[2]FatherDanny BraxtonMotherCheryl BraxtonBrothersHeath BraxtonHalf-brothersKyle BraxtonCasey BraxtonSonsCasey BraxtonNephewsRocco Scott-BraxtonHar...

維文 (新加坡)

本條目存在以下問題，請協助改善本條目或在討論頁針對議題發表看法。 此生者传记条目需要补充更多可供查證的来源。 (2015年9月18日)请协助補充可靠来源，无法查证的在世人物内容将被立即移除。 此條目過於依赖第一手来源。 (2015年9月18日)请補充第二手及第三手來源，以改善这篇条目。 此條目需要补充更多来源。 (2015年9月18日)请协助補充多方面可靠来源以改善这篇条�...

 

Natale in casa Cupiello

Natale in casa CupielloCommedia in tre atti Una scena della versione televisiva del 1977 AutoreEduardo De Filippo Lingua originalenapoletano, italiano GenereTeatro napoletano Composto nel1931 Prima assoluta25 dicembre 1931Kursaal di Napoli Personaggi Luca Cupiello Concetta, sua moglie Tommasino, loro figlio, detto Nennillo Ninuccia, la figlia Nicola, suo marito Pasqualino, fratello di Luca Raffaele, portiere Vittorio Elia Il dottore Carmela Olga Pastorelli Luigi Pastorelli Alberto Armida Roma...

 

Williamson College

Williamson CollegeFormer namesWilliamson Christian College (1997–2013)[1]MottoEquipping Minds, Engaging Hearts, and Following ChristTypePrivate collegeEstablished1997[2]AccreditationAssociation for Biblical Higher EducationAffiliationEvangelical Council For Financial AccountabilityReligious affiliationNondenominational ChristianPresidentEd Smith[3]Academic staff2 full-time, 31 part-timeAdministrative staff12Students60Postgraduates9LocationFranklin, Tennessee, Uni...

List of caves

This is a dynamic list and may never be able to satisfy particular standards for completeness. You can help by adding missing items with reliable sources. This is a list of caves of the world that have articles or that are properly cited. They are sorted by continent and then country. Caves which are in overseas territories on a different continent than the home country are sorted by the territory's continent and name. Africa The Cango caves in western cape. African cave paintings Lithic Ind...

 

Environment of Nevada

Berlin-Ichthyosaur State Park The environment of Nevada comprises diverse biotas, climates, and geologies. Environmental regulations and the environmental movement have aimed to respond to environmental threats. Renewable Portfolio Standard External image Electricity in Nevada 2001—2017 In 1997 Nevada passed a Renewable Portfolio Standard as part of their 1997 Electric Restructuring Legislation (AB 366) It required any electric providers in the state to acquire actual renewable electric gen...

 

MC Ren

American rapper, songwriter and record producer Not to be confused with MC Rene. MC RenMC Ren in 1990BornLorenzo Jerald Patterson (1969-06-16) June 16, 1969 (age 54)Compton, California, U.S.Other namesVillainRuthless VillainThe Villain in BlackRebel VillainNation VillainEducationDominguez High SchoolOccupationsRapperrecord producersongwriterYears active1987–presentSpouse Yaasamen Alaa ​(m. 1993)​Children5Musical careerGenres West Coast hip hop gan...

Isle of Dogs

Isle of DogsPoster film Isle of DogsSutradaraWes AndersonProduserWes AndersonScott RudinSteven RalesJeremy DawsonDitulis olehWes AndersonCeritaWes AndersonRoman CoppolaJason SchwartzmanKunichi NomuraPemeranKoyu RankinBryan CranstonEdward NortonBill MurrayJeff GoldblumBob BalabanScarlett JohanssonF. Murray AbrahamLiev SchreiberTilda SwintonKunichi NomuraKen WatanabeNaratorCourtney B. VancePenata musikAlexandre DesplatSinematograferTristan OliverPenyuntingRalph FosterEdward BurschPerusaha...

 

Alice Mary Longfellow

Alice Mary LongfellowLongfellow in 1921Born(1850-09-22)September 22, 1850Cambridge, MassachusettsDiedDecember 7, 1928(1928-12-07) (aged 78)Cambridge, MassachusettsParents Henry Wadsworth Longfellow Frances Elizabeth Appleton Relatives Ernest Wadsworth Longfellow (brother) Stephen Longfellow (grandfather) Alice Mary Longfellow (September 22, 1850 – December 7, 1928) was a philanthropist, preservationist, and the eldest surviving daughter of the American poet Henry Wadsworth Longfellow. ...

 

U-21-Fußball-Europameisterschaft 1996

U-21-Fußball-Europameisterschaft 1996 UEFA Under-21 Championship Anzahl Nationen 4 (von 44 Bewerbern) Europameister Italien Italien (3. Titel) Austragungsort Spanien Spanien Eröffnungsspiel 28. Mai 1996 Endspiel 31. Mai 1996 Spiele 4 Tore 7 (⌀: 1,75 pro Spiel) Torschützenkönig Spanien Raúl González Blanco (3 Tore) Die 13. U-21-Fußball-Europameisterschaft wurde wieder von Italien gewonnen. Es war der dritte Sieg hintereinander für die Italiener. Deutsch...

MTV2

American pay television channel This article is about the US television channel. For other uses, see MTV2 (disambiguation). Television channel MTV2CountryUnited StatesBroadcast areaUnited StatesProgrammingLanguage(s)EnglishSpanish (via SAP audio track)Picture format1080i HDTV(downscaled to letterboxed 480i for the SDTV feed)OwnershipOwnerParamount Media Networks (Paramount Global)ParentMTV Entertainment GroupSister channels List Nickelodeon Nick Jr. Channel Nicktoons TeenNick CBS CBS Sports N...

 

Danemark aux Jeux olympiques de la jeunesse d'hiver de 2012

Cet article est une ébauche concernant le Danemark et les Jeux olympiques. Vous pouvez partager vos connaissances en l’améliorant (comment ?) selon les recommandations des projets correspondants. Danemark aux Jeux olympiques de la jeunesse d'hiver de 2012 Code CIO DEN Comité Comité olympique danois Site web www.dif.dk Lieu Innsbruck Participation 1re aux Jeux olympiques de la jeunesse d'hiver Athlètes 5 dans 3 sports Porte-drapeau Philip Due Schmidt[1] MédaillesRang : Or0 A...

 

Лавров, Сергей Борисович (географ)

В Википедии есть статьи о других людях с такой фамилией, см. Лавров; Лавров, Сергей; Лавров, Сергей Борисович. Сергей Борисович Лавров Дата рождения 26 мая 1928(1928-05-26) или 1928[1] Место рождения Ленинград, РСФСР, СССР Дата смерти 17 июля 2000(2000-07-17) или 2000[1] Мест�...

Championnat d'Italie de football 2003-2004

Cet article est une ébauche concernant une compétition de football et l’Italie. Vous pouvez partager vos connaissances en l’améliorant (comment ?) selon les recommandations des projets correspondants. Serie A2003-2004 Généralités Sport Football Organisateur(s) FIGC Édition 102e Lieu(x) Italie Date du 30 août 2003 au 16 mai 2004 Participants 18 Matchs joués 306 Site web officiel Lega-calcio.it Hiérarchie Hiérarchie 1er échelon Niveau inférieur Serie B 2003-2004 Palm...

 

Nikolai Bugaev

Russian mathematician (1837–1903) This article includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations. Please help improve this article by introducing more precise citations. (September 2015) (Learn how and when to remove this message) Nikolai BugaevBorn(1837-09-14)September 14, 1837Georgia, Russian EmpireDiedJune 11, 1903(1903-06-11) (aged 65)Moscow, Russian EmpireNationalityRussianAlma materImperial Mos...