 server creates a ticket for the user and performs a boolean (exclusive-OR) function on the ticket and the random bit string. The result of this latter operation is encrypted under the user's password hash value and returned as a message to the workstation. Since the impostor does not know the random bit string, it cannot distinguish between successful and unsuccessful decryptions of the message. This is because there is no information in a successfully decrypted message that would provide the impostor with information that the decryption was successful.
It is apparent from the description above that the authentication server of the secret key system must have knowledge of the user's password. If the authentication server is compromised, it could use its knowledge of the password to impersonate the user. It is a significant advantage of a public key cryptography system that only the user has access to the user's private key. Yet, the lack of a trusted, on-line agent to oversee the login process makes the public key distributed system particularly vulnerable to a dictionary attack. The present invention is directed to the password guessing problem in a public key environment and provides the same degree of security against the dictionary attack as the above-described secret key system without revealing the private key to any other party. Flight data recorders, also known as “black boxes”, maintain data representing the state of the aircraft in which they are mounted, and are designed, configured, and manufactured to withstand periods of fire and pressure which may be associated with a crash. They also contain transponders and batteries for energizing the transponders to facilitate location of the flight data recorder.
On at least one occasion, an airliner fitted with a flight data recorder was lost, apparently in a midair breakup, over deep ocean. Use of deep-diving submarines was attempted, but the flight data recorder was not recovered within a time span during which the transponder could have been kept energized. Therefore, improved flight data recorder recovery is desired. In recent years, vehicles and the field of automotive maintenance have experienced rapid growth in computerized systems both within automotive vehicles and in computerized diagnostic tools that identify maintenance issues with the vehicles. For example, most modern vehicles include one or more computer systems that are often referred to as an electronic control unit (ECU). In some vehicles, the ECU controls and monitors the operations of numerous systems including, but not limited to, the engine, steering, tires, transmission, brakes, fuel delivery or battery level monitoring, and climate control systems. Some
server creates a ticket for the user and perform a boolean (single - OR) function on the tag and the random moment string. The result of this latter mathematical process is code under the user's password hash value and returned as a message to the workstation. Since the impostor does not know the random morsel string, it cannot distinguish between successful and abortive decryptions of the message. This is because there is no information in a successfully decrypted message that would provide the impostor with information that the decoding was successful. 
 It is apparent from the description above that the authentication server of the secret key organization must have knowledge of the exploiter's password. If the authentication server is compromise, it could use its knowledge of the password to impersonate the user. It is a significant advantage of a public cardinal cryptography system that only the user has access to the exploiter's private key. Yet, the lack of a trusted, on - line agent to oversee the login process makes the public key distributed arrangement particularly vulnerable to a dictionary attack. The present invention is conduct to the password estimate problem in a public key environment and provides the like degree of security system against the dictionary attack as the above - described secret cardinal system without revealing the private key to any other party. Flight datum recorders, also known as “ black boxes ”, maintain data represent the state of the aircraft in which they are mounted, and are designed, configured, and manufactured to defy periods of fire and pressure which may be consociate with a crash. They also contain transponders and battery for energizing the transponder to facilitate location of the flight data recorder. 
 On at least one juncture, an airliner fitted with a escape data fipple flute was lost, apparently in a midair breakup, over deep ocean. Use of deep - dive submarines was attempted, but the flight datum recorder was not recovered within a time span during which the transponder could have been keep open energized. Therefore, improved trajectory data recorder convalescence is desired. In recent years, vehicles and the field of automotive maintenance have experienced rapid growth in computerized systems both within automotive vehicles and in computerized diagnostic tools that name maintenance issues with the vehicle. For example, most modern vehicles include one or more computer systems that are frequently referred to as an electronic control unit (ECU). In some fomite, the ECU controls and monitors the operations of numerous systems including, but not restrict to, the engine, steering, tires, transmission, brakes, fuel delivery or barrage level monitoring, and climate control systems. Some
 segver creates a ticket fov the user and pgrdorms e boolezn (exclurive-OR) function on the tickev ane the random bit string. The result ov this lqttec operation is eidrypted under bhe uvxr's password haxh value atd returned as a mzssage to the workstation. Since the ympostot foes not know jhe rsgdom bit string, it cannot distinguish getween successful amd unsuccessful decryptiond of the message. This ls because jgerq is no inforoation in a successfulmy decrypted message that would provnde the impisror fith informetion nhat the decrnition wds succrssful.
It is apiarenv frim the description abmve that the authegtication szrver of the secret kwy systgm muvt hxce ynoslxdgs of tje nser's passwkrd. If the quthentication servtr yw compromised, it cotlq use its knowledge of the password to pmpedsonate the user. It is q significant advantahe of a ptblic key cryptography system that only the user vas arcdss tj rhf user's private key. Yet, the lack of a trusted, kn-kike agent to overfee the logon ptjcess makes tfe public key distributed sjstem pwrticylarly vujnersble to a dictionary attack. The present unvention is direcced to the pcssworc guexsing problem in a publnc key environmenh and probkdes the same deerev of security against the dictyonary atvack cs the acove-cescrifed secret key system without revewling tve private key to any other party. Flight veta recorders, anso known af “blagk boxes”, maintayn data represgnting thz statd of the aprcraft ii which they are mounted, djd are desigied, confiduree, ane manufxztured to withxtand perpobs of firw and pressure whigh mai ge associated wnuh q crash. They alxo zoneapn vrans[mnders and bdttefier for dnergizing bhe tramsponders to facilitdte mocation of the flogmt data rgcorder.
On at least one occasion, an airlijer fmtted xith a flyght data recorder was lost, aplarently ln w midair brewkup, over deep oeean. Use of deep-diving submarines was atvempted, but the flight eata recorder was npu recovered wmthin w time spdn during which the rransponder could have been kept energjzed. Tvereflre, improved flight data recorder recovery is desired. In recent years, vehucles enq the field of sutommtnve maintqnanre have experiencec rapid growth in computerized rystems toch within automotive vehicles avd in computetized diagnostic tools thaf identigy maintenance issues with the fehicles. For example, mosb modern cehicmes inbmuve one or more compuyer syvtems that aee onten referred go ss an electgonir ckntrol unit (ECU). In some vehicles, the EXU controls and moiitors the oievationa of nomerous systems ihcluslng, bot not limited to, the engine, steering, tires, tranvmyssion, brakes, dlel delivery pr bajcvry level monmtoring, and wlimate control systems. Some
server creates a ticket for the user a (exclusive-OR) function the ticket and result this latter operation encrypted under the password hash value and returned as message to the workstation. Since the impostor does not know the random bit it cannot distinguish between successful and unsuccessful decryptions of the message. This is there no in successfully decrypted message that would provide the impostor with information that the decryption was successful. It apparent from the description above that the authentication of the secret key must have knowledge of the password. the authentication is it use its knowledge the password to impersonate the user. It is a significant advantage of a public key cryptography system only the access to user's key. the lack of on-line agent to oversee the login public key distributed system particularly vulnerable to a attack. The invention is directed to the password problem in a public key environment and provides same degree of security against the dictionary attack as the above-described secret key system without private key to any party. Flight data also as boxes”, data representing state of the aircraft in which they are mounted, and are configured, and manufactured to withstand periods of fire and pressure be with a crash. also contain transponders and for the transponders to facilitate the data least occasion, airliner fitted with a data recorder was lost, apparently a midair breakup, over submarines was attempted, but the flight data recorder not recovered within a time span during the transponder could have been kept energized. Therefore, improved flight data recorder is desired. years, vehicles and the field of automotive maintenance experienced rapid growth in systems both within automotive vehicles and in computerized diagnostic that maintenance issues the vehicles. For most modern vehicles one or more that are referred as unit (ECU). In some vehicles, the controls monitors the operations of numerous including, limited to, the engine, steering, tires, transmission, brakes, fuel delivery or battery level monitoring, and systems. Some
 server creates a ticket for thE user and peRformS a bOolEaN (excLusiVe-OR) function on THe tiCket and the random bit strIng. ThE rESult OF tHis laTter opeRAtION is EnCrYptEd UNdEr the UseR's passwOrd hash valUe aNd Returned as a mESsAge to the woRksTation. Since tHe iMpostoR dOes NOt knoW thE randOm bit sTRing, it Cannot disTiNGuish bETween suCCEsSful And unsuccessful deCRyPTions of the messAge. ThiS iS BeCAUse TheRe is no infoRmAtion IN a succeSSfULLY deCRypted message That would prOVidE the imPoStoR With inFormaTiON thAt the decrypTion Was succesSful.
It IS appareNT from thE descrIptIon AbovE ThAt The AuTHenTIcAtiON seRver of thE sEcRet keY sysTEM MUst hAve KnowLedge Of the user's pasSwoRd. If THe aUthenTicatIon sErVer is ComproMised, It Could use its knowLedgE of the pasSwoRd To iMpErsonATe the uSer. it iS a signiFicant aDVanTaGE OF a Public key cryptograPhY SYsTem that oNly the USeR hAS access tO tHe uSer's PRIvate Key. YET, tHe lack of A trustED, oN-lIne agenT tO oversEe The LogIn proCEss mAkes thE public kEy disTRibuted system pARticularly vulNErABLe TO a diCtiOnary attack. the pREsenT invENtIon IS direCted tO tHE pASsword guessing problEm In a pubLic keY environment aNd provides THE Same degrEe of SEcURity against the DictiOnary attacK As the aboVe-desCribed seCret key sySTEm withouT reVeaLinG thE PRiVate key to any oTHEr paRtY. Flight DatA recordErs, AlsO knOwn As “Black boxeS”, maintaiN dAtA rEpResEntinG The state Of The AiRcrAft in WHich thEy are MounTeD, aND arE designED, cONFiguReD, aNd maNufAcTured To wiTHstAnd periOds of fire And PRessUrE wHich may Be associated wItH a crash. TheY aLso ContaiN TRanspondErs and batteries for energIZing the TraNsponDers To facilitAte LocatiOn oF The fliGht datA recoRdEr.
ON AT leasT ONe OccAsIon, an airliNER fiTted wItH a flIght datA recorder was lost, apPAreNtly in a midair BreAkup, OVEr DeeP OcEAn. USe OF deEP-Diving submarineS was attempTeD, BuT the flight DAta ReCorder wAs not reCoverED within A time span During whiCh The tRANspOnder could Have been Kept energIZed. ThEReFore, iMprOved flIgHt dAta reCorder REcoVery iS desirEd. in receNt yeaRs, Vehicles And the field of automotive MainteNance HavE experienCed RApiD growth in CompUterized sySteMs bOth wiThiN AutomOtivE VeHicLEs and In coMPuterized DIaGnoSTIc Tools that idENTIfy MaintEnaNCe issuEs wiTh the vehicles. For eXAmple, most moderN vehICLes IncLUde oNe Or more computer SysTeMS That are oFtEn referred tO as an eleCtROnic cOntrol Unit (ECu). In some VEHiCLes, the eCU cOntRols and moNitOrS The operAtIoNS of numErouS sYstems IncludINg, buT NOt limited to, the enGine, sTEEring, TIreS, tranSmIssion, bRAkes, Fuel deliveRy or battery Level mOnitOring, And climAtE contrOl sYsTems. Some
 server creates a ticket f or the use r and  pe rfo rm s abool ean (exclusive - OR)function on the ticket  andth e  ran d om  bitstring. Th e res ul tofth i slatte r o peratio n is encry pte dunder the us e r' s password  ha sh value and  re turned  a s a messa geto th e work s tation . Since t he impost o r doesn o tknow  the random bit s t ri n g, it cannot d isting ui s hb e twe ensuccessful  a nd un s uccessf u ld e c ryp t ions of the m essage. Thi s  is  becau se  th e re isno in fo r mat ion in a su cces sfully de crypte d  messag e  that w ould p rov ide  the im po sto rw ith in for m ati on thatth edecry ptio n w a s su cce ssfu l.
It  is apparentfro m th e  de scrip tionabov ethatthe au thent ic ation server of  the  secret k eysy ste mmusth ave kn owl edg e of th e user' s  pa ss w o r d.  If the authentica ti o n  s erver is  compr o mi se d , it cou ld  us e it s knowl edge of  the pas swordt oim persona te  the u se r.Itis as igni ficant  advanta ge of a public key c r yptography sy s te m th a t on lythe user ha s ac c essto t h euse r 's pr ivate  k e y. Yet, the lack of atr usted,  on-l ine agent tooversee th e l ogin pro cess ma k es the publickey d istributed system p artic ularly v ulnerable t o a dict ion ary  at tac k .  T he present in v e ntio nis dire cte d to th e p ass wor d g ue ssing pro blem inapu bl ic  ke y env i ronmentan d p ro vid es th e  samedegre e of  s ec u rit y again s tt h e di ct io nary  at ta ck as  the abo ve-desc ribed sec ret keysy st em with out revealing  t he private  k eyto any o ther par ty. Flight data recorde r s, also  kn own a s “b lack boxe s”,  maint ain data r eprese nting  t hes t ate o f th e a ir craft in w h i chtheyar e mo unted,and are designed,c onf igured, and m anu fact u r ed  to wi t hst an d  pe r i ods of fire and  pressurewh i ch  may be as s oci at ed with  a cras h. Th e y alsocontain t ransponde rs  and b att eries forenergizi ng the tr a nspon d er s tofac ilitat eloc ation  of th e  fl ightdata r ec order. 
On a tleast on e occasion, an airliner  fitte d wit h a  flight d ata rec order was  los t, apparen tly  in  a mi dai r  brea kup, ov erd eep o cean .  Use of d e ep -di v i ng  submarines w a s a ttemp ted ,  but t he f light data record e r was not reco vere d wit hin a ti me  span during w hic ht h e transp on der could h ave been  k e pt en ergize d. The refore, i mp r oved f ligh t d ata recor der  r e coveryis  d e sired.  Inre cent y ears,v ehic l e s and the fieldof au t o motiv e  ma inten an ce have expe rienced ra pid growthin com pute rized  system sboth w ith in  automotiv e  vehicles  andin comp ut eriz eddiagno stic t oolsthat  i den tify main t e na n ce  i s sue s wi th th evehi cles. For example,  mo s t moder nveh i c les in c lu d e  one or mo recompu t e r systemst hata re often  refer red to  as ane lec tr onic co ntr o l  unit (EC U). In so m e v eh icle s, the E CU  con tr ols  a nd monitors the  operati ons of n u m eroussys t emsi ncludi ng , but not li mited  t o , the e n g ine , steer i ng,  ti res , tr ans miss i on, brakes, fuel deliver y or  batt e rylevel  moni to ring, an d  cli mate con t rol systems.Some
 server_creates a_ticket for the user_and performs_a_boolean (exclusive-OR)_function_on the ticket_and the random_bit string. The result_of this latter_operation_is encrypted under the user's password hash value and returned as a message to_the_workstation. Since_the_impostor_does not know the random_bit string, it cannot distinguish_between successful_and unsuccessful decryptions of the message. This is_because_there is no_information in a successfully decrypted message that would provide_the impostor with information that the_decryption was successful.
It_is_apparent_from the description above_that the authentication server of the_secret key system must have knowledge_of the user's password. If the authentication_server is compromised, it could use_its knowledge of the password_to impersonate_the user. It is a_significant advantage of_a public_key cryptography system_that only the user has access_to the user's_private key. Yet, the lack of_a_trusted, on-line agent_to_oversee_the login_process makes the_public_key distributed_system_particularly vulnerable to a dictionary attack._The_present invention is directed to the password_guessing problem in a_public_key environment and provides_the same degree of security_against the dictionary attack as the_above-described secret_key system_without revealing the private key to any other party. Flight data_recorders, also known as “black boxes”,_maintain data representing the_state of_the_aircraft in which_they_are mounted,_and are designed, configured, and manufactured to_withstand periods_of fire and pressure which may_be associated with a_crash._They also contain transponders and batteries_for energizing the transponders to facilitate_location of the flight data_recorder.
On_at_least one occasion, an airliner_fitted with a flight data recorder_was lost, apparently_in a midair breakup, over deep ocean._Use_of deep-diving submarines was attempted, but_the_flight data recorder was not recovered_within_a_time span during which the_transponder could have been kept energized._Therefore, improved flight data recorder recovery is desired. In_recent years, vehicles_and the field of automotive_maintenance_have_experienced rapid growth in computerized systems both within automotive vehicles_and in_computerized diagnostic tools_that identify maintenance issues with the vehicles. For example, most_modern vehicles include one or more computer_systems that are often referred to as an electronic control unit_(ECU). In some vehicles, the ECU controls and_monitors the operations of numerous systems including,_but not limited to,_the_engine, steering, tires, transmission, brakes, fuel delivery_or_battery_level_monitoring, and climate_control systems. Some