|
|
|
|
|
|
|
1. WordNet® 3.0 (2006) |
back door
n 1: a secret or underhand means of access (to a place or a
position); "he got his job through the back door" [syn:
back door, backdoor]
2: an undocumented way to get access to a computer system or the
data it contains [syn: back door, backdoor]
3: an entrance at the rear of a building [syn: back door,
backdoor, back entrance]
|
2. The Collaborative International Dictionary of English v.0.48 |
Back door \Back" door"\
A door in the back part of a building; hence, an indirect
way. --Atterbury.
[1913 Webster]
|
3. The Jargon File (version 4.4.7, 29 Dec 2003) |
back door
n.
[common] A hole in the security of a system deliberately left in place by
designers or maintainers. The motivation for such holes is not always
sinister; some operating systems, for example, come out of the box with
privileged accounts intended for use by field service technicians or the
vendor's maintenance programmers. Syn. trap door; may also be called a
wormhole. See also iron box, cracker, worm, logic bomb.
Historically, back doors have often lurked in systems longer than anyone
expected or planned, and a few have become widely known. Ken Thompson's
1983 Turing Award lecture to the ACM admitted the existence of a back door
in early Unix versions that may have qualified as the most fiendishly
clever security hack of all time. In this scheme, the C compiler contained
code that would recognize when the login command was being recompiled and
insert some code recognizing a password chosen by Thompson, giving him
entry to the system whether or not an account had been created for him.
Normally such a back door could be removed by removing it from the source
code for the compiler and recompiling the compiler. But to recompile the
compiler, you have to use the compiler ? so Thompson also arranged that the
compiler would recognize when it was compiling a version of itself, and
insert into the recompiled compiler the code to insert into the recompiled
login the code to allow Thompson entry ? and, of course, the code to
recognize itself and do the whole thing again the next time around! And
having done this once, he was then able to recompile the compiler from the
original sources; the hack perpetuated itself invisibly, leaving the back
door in place and active but with no trace in the sources.
The Turing lecture that reported this truly moby hack was later published
as ?Reflections on Trusting Trust?, Communications of the ACM 27, 8 (August
1984), pp. 761--763 (text available at http://www.acm.org/classics/). Ken
Thompson has since confirmed that this hack was implemented and that the
Trojan Horse code did appear in the login binary of a Unix Support group
machine. Ken says the crocked compiler was never distributed. Your editor
has heard two separate reports that suggest that the crocked login did make
it out of Bell Labs, notably to BBN, and that it enabled at least one
late-night login across the network by someone using the login name ?kt?.
|
4. The Free On-line Dictionary of Computing (30 December 2018) |
back door
wormhole
(Or "trap door", "wormhole"). A hole in the
security of a system deliberately left in place by designers
or maintainers. The motivation for such holes is not always
sinister; some operating systems, for example, come out of
the box with privileged accounts intended for use by field
service technicians or the vendor's maintenance programmers.
See also iron box, cracker, worm, logic bomb.
Historically, back doors have often lurked in systems longer
than anyone expected or planned, and a few have become widely
known. The infamous RTM worm of late 1988, for example,
used a back door in the BSD Unix "sendmail(8)" utility.
Ken Thompson's 1983 Turing Award lecture to the ACM
revealed the existence of a back door in early Unix versions
that may have qualified as the most fiendishly clever security
hack of all time. The C compiler contained code that would
recognise when the "login" command was being recompiled and
insert some code recognizing a password chosen by Thompson,
giving him entry to the system whether or not an account had
been created for him.
Normally such a back door could be removed by removing it from
the source code for the compiler and recompiling the compiler.
But to recompile the compiler, you have to *use* the compiler
- so Thompson also arranged that the compiler would *recognise
when it was compiling a version of itself*, and insert into
the recompiled compiler the code to insert into the recompiled
"login" the code to allow Thompson entry - and, of course, the
code to recognise itself and do the whole thing again the next
time around! And having done this once, he was then able to
recompile the compiler from the original sources; the hack
perpetuated itself invisibly, leaving the back door in place
and active but with no trace in the sources.
The talk that revealed this truly moby hack was published as
["Reflections on Trusting Trust", "Communications of the ACM
27", 8 (August 1984), pp. 761--763].
[Jargon File]
(1995-04-25)
|
|
|
Thesaurus Results for back door:
|
1. Moby Thesaurus II by Grady Ward, 1.0 |
French door, afterpart, afterpiece, archway, back, back road, back seat, back side, back stairs, back street, back way, backstairs, barway, behind, bolt-hole, breech, bulkhead, by-lane, bypass, bypath, byroad, bystreet, byway, carriage entrance, cellar door, cellarway, clandestine, covert, covert way, detour, door, doorjamb, doorpost, doorway, escalier derobe, escape hatch, escape route, feline, front door, furtive, gate, gatepost, gateway, hatch, hatchway, heel, hidlings, hind end, hind part, hindhead, hole-and-corner, hugger-mugger, lintel, occiput, porch, portal, porte cochere, posterior, postern, privy, propylaeum, pylon, quiet, rear, rear end, rearward, reverse, roundabout way, scuttle, secret exit, secret passage, secret staircase, shifty, side door, side road, side street, skulking, slinking, slinky, sly, sneaking, sneaky, stealthy, stern, stile, storm door, surreptitious, tail, tail end, tailpiece, threshold, tollgate, trap, trap door, turnpike, turnstile, under-the-counter, under-the-table, undercover, underground, underground railroad, underground route, underhand, underhanded, unobtrusive |
|
|
|
|
|
Common Misspellings > |
back door aback door abck door babck door ack door bback door bcak door bacak door bck door baack door bakc door backc door bak door bacck door bac kdoor back kdoor bac door backk door backd oor back d oor backdoor back door back odor back dodor back oor back ddoor back dooor back dor back dooor back doro back dooro back dor back dooor back doror back doo back doorr fack door bfack door fback door gack door bgack door gback door hack door bhack door hback door vack door bvack door vback door nack door bnack door nback door ack door b ack door back door bqck door baqck door bqack door bwck door bawck door bwack door bsck door basck door bsack door bxck door baxck door bxack door bzck door bazck door bzack door b ck door ba ck door b ack door beck door bick door bock door buck door bask door bacsk door basck door badk door bacdk door badck door bafk door bacfk door bafck door baxk door bacxk door baxck door bavk door bacvk door bavck door ba k door bac k door ba ck door bacu door backu door bacuk door baci door backi door bacik door baco door backo door bacok door bacj door backj door bacjk door bacl door backl door baclk door bacm door backm door bacmk door bac, door back, door bac,k door bac. door back. door bac.k door back woor back dwoor back wdoor back eoor back deoor back edoor back roor back droor back rdoor back soor back dsoor back sdoor back foor back dfoor back fdoor back xoor back dxoor back xdoor back coor back dcoor back cdoor back voor back dvoor back vdoor back oor back d oor back door back d99r back do99r back d99or back d((r back do((r back d((or back d00r back do00r back d00or back diir back doiir back diior back dppr back doppr back dppor back dkkr back dokkr back dkkor back dllr back dollr back dllor back daar back deer back duur back doo4 back door4 back doo4r back doo$ back door$ back doo$r back doo5 back door5 back doo5r back dooe back doore back dooer back doot back doort back dootr back dood back doord back doodr back doof back doorf back doofr back doog back doorg back doogr Definition commonly spelled as: Defanition or Defenition, Synonym as: Synonim, Sinonym or Sinonim, Thesaurus as: Thesorus or Thesauris, Dictionary as: Dictionery or Dictionry and Define is usually not misspelled. What does mispell meen? It Meens...
Full Map Index: Å Norway-Am Timan Chad |
Ama United States of America-Audon France |
Audouville-la-Hubert France-Baskil Turkey |
Baskin United States of America-Bindoy Philippines |
Bindoy Philippines-Breuilpont France |
Breukelen Netherlands-Campofelice di Fitalia Italy |
Campofelice di Roccella Italy-Champigny France |
Champigny-en-Beauce France-Colle San Magno Italy |
Colle Sannita Italy-Damulog Philippines |
Damurhuda Bangladesh-Duliāgaon India |
Duliajan No.1 India-Ethridge United States of America |
Étienville France-Frignano Italy |
Frignicourt France-Gouhenans France |
Gouillons France-Hasselbach Germany |
Hasselbach Germany-Hurlock United States of America |
Huron United States of America-Jovellanos Cuba |
Jovellar Philippines-Kirchzell Germany |
Kircubbin United Kingdom-La Gomera Guatemala |
La Gonfrière France-Le Hohwald France |
Le Hommet-dArthenay France-Loma de Gato Philippines |
Loma de Juárez Mexico-Mālpur India |
Mālpura India-Memphis United States of America |
Memphis United States of America-Montería Colombia |
Monteriggioni Italy-Navalilla Spain |
Navalmanzano Spain-Noyelles-lès-Seclin France |
Noyelles-lès-Vermelles France-Pachelma Russia |
Pachgaon India-Piégut-Pluviers France |
Piekary Śląskie Poland-Prilep Macedonia |
Přílepy Czech Republic-Reuil-en-Brie France |
Reuilly France-Şag Romania |
Şag Romania-Saint-Puy France |
Saint-Python France-Santa Rita Panama |
Santa Rita Venezuela-Sewarhi India |
Sewen France-Sparbu Norway |
Spardorf Germany-Tamparan Philippines |
Tampayan Philippines-Tottington United Kingdom |
Tottleben Germany-Valdivia Chile |
Valdivia Colombia-Villeneuve-le-Roi France |
Villeneuve-lès-Avignon France-White City United States of America |
White City Canada-Żywiec Poland |
|
Most Popular Searches: Define Misanthrope, Define Pulchritudinous, Define Happy, Define Veracity, Define Cornucopia, Define Almuerzo, Define Atresic, Define URL, Definitions Of Words, Definition Of Get Up, Definition Of Quid Pro Quo, Definition Of Irreconcilable Differences, Definition Of Word, Synonyms of Repetitive, Synonym Dictionary, Synonym Antonyms. See our main index and map index for more details.
|
©2011-2024 ZebraWords.com - Define Yourself - The Search for Meanings and Meaning Means I Mean. All content subject to terms and conditions as set out here. Contact Us, peruse our Privacy Policy |
|