History Main / TrustPassword

* In ''WesternAnimation/SouthPark'', Cartman wants to be a HumanPopsicle so that he won't have to wait for the UsefulNotes/NintendoWii to come out. He badly overshoots his goal and ends up in a BadFuture, where there's a war going on which [[SkewedPriorities prevents him from playing the Wii]]. He calls his past self to fix things and tries to convince him of his identity by explaining things only he would know, liking drinking Ovaltine and putting Clyde Frog in the closet before going to Butters and trying to freeze himself. But his past self merely thinks someone was spying on him and is not convinced.

* ''Series/TheGoodies''. In "Invasion of the Moon Creatures", the password for getting into Graeme's missile control room is Bill shouting, "Let us in, you great Nana!"

* From ''Franchise/{{Superman}}'' comics:

* ''Franchise/JusticeLeagueOfAmerica'': During the Obsidian Age arc, in which the entire League is killed and their souls trapped by an ancient Atlantean sorceress, it's revealed that Franchise/{{Batman}}'s passcode for ComicBook/{{Nightwing}} is "The Daring Young Man on the Flying Trapeze"; not only are they song lyrics, but they also refer to Dick Grayson's boyhood career.
* ''ComicBook/MortadeloYFilemon'' have an [[SparseListOfRules arbitrarily catalogued]] number of trust passwords. A RunningGag is for the password to be very offensive to some group or collective that happens to be within earshot. [[HilarityEnsues A beating ensues]].

* Defied in an old ''ComicBook/XMen'' story. When ComicBook/EmmaFrost tries to convince ComicBook/KittyPryde that [[FreakyFridayFlip she is in fact]] [[Characters/MarvelComicsStorm Storm]] and that the actual Frost had [[GrandTheftMe forcibly body-jacked]] her to infiltrate the X-Men, Pryde understandably points out that "Something only I would know," is a means of identification trivially bypassed by a low-ethics telepath that has had a couple of hours to dig through the requester's brain.

* In ''[[http://archiveofourown.org/works/10993269/chapters/24485088 The Tie that Binds,]]'' a Franchise/MarvelCinematicUniverse crossover centering on ''Series/AgentsOfSHIELD'', Agent Coulson is held prisoner by Thanos, whose agents showed him faked footage of his team being tortured, and Melinda May being killed. Meanwhile [[Film/GuardiansOfTheGalaxy2014 Gamora]] makes contact with May on Earth and asks for a message to pass along to Coulson when they plan to rescue him from prison. May's message, which convinces Coulson that she's alive and the rest of his team are safe, is [[Recap/AgentsOfSHIELDS4E21TheReturn "Tell Phil I'm going to kick his ass for opening the Haig without me."]]

* ''Film/{{Tenet}}''--the TitleDrop is a TrustPassword for members of eponymous organisation [[SecretHandshake when combined with interlacing the hands]]. Also "We live in a twilight world" and its response phrase "And there are no friends at dusk", used by the Protagonist and his CIA team in the ActionPrologue. The BigBad uses the phrase when meeting the Protagonist, implying he works for the CIA as well (though the Protagonist pretends not to recognise it).

** In ''Film/AvengersEndgame'', [[spoiler:A time traveling Captain America has returned to the time of ''Film/TheAvengers2012'' and he needs to get the scepter for the modern day Avengers' plan. Surrounded by Agent Sitwell and S.T.R.I.K.E. team members, he knows he can't fight them or blow their cover as HYDRA moles at this point, so Cap utters the "Hail HYDRA" salute to them, befuddling the entire group and letting Cap walk out with the scepter.]]

* In the ''Literature/WarriorCats'' book ''[[Recap/WarriorCatsTheSilentThaw The Silent Thaw]]'', [[spoiler:in order to prove to Squirrelflight that he's met Bramblestar's true ghost and that the living Bramblestar is an impostor possessing his body, Rootpaw listens to ghost-Bramblestar and describes to Squirrelflight a private conversation that she and Bramblestar had had after Leafpool's death.]]

** ''Literature/GhostStory'': When Harry reappears after his vanishing six months prior with his friends not knowing what happened to him, he is bombarded with questions from allies to all matters of {{Call Back}}s in the previous twelve books to confirm his identity and not some imposter or doppelganger. [[spoiler:This is all the more important because at this moment, Harry is a spirit and talking through an ectomancer. It finally takes Harry's cat who can see him rubbing against his intangible leg and Molly, Harry's apprentice who has gone a dark path since his death, to confirm it is him]].

** Used again in Season 6, when the villainous Izel is capable of possessing people's bodies and imitating their mannerisms, but can't access their memories beyond what she already knows of them. This results in a very tense scene where the agents all share half of a secret they know about somebody else in the room, which the other person then has to complete, thus proving that both individuals are really who they say they are. (Example: [[spoiler:Mack, as the new director, is the only person who knows that Daisy donates part of her paycheck every month, and asks her to confirm where it goes. She reveals that she gives it to [[TheLostLenore Lincoln's]] sister.]]) Naturally, the first person to flat-out refuse to comply can't give a good reason for doing so, and is quickly identified as being the one who's possessed.

-->'''Giles:''' Cordelia, it's me! It's me!\\

** "[[Recap/DoctorWhoS30E13JourneysEnd Journey's End]]": [[Recap/DoctorWhoS28E13Doomsday Two seasons earlier]], [[spoiler:Rose Tyler was locked in an alternate universe and separated from the Doctor, who only had the energy to send her one message to tell her he loves her. However, his energy source runs out at "Rose Tyler, I--".]] In this episode, there are [[DoppelgangerReplacementLoveInterest two Doctors]], one of which is [[spoiler:human while the other one is still a Time Lord. The human Doctor is offering, and able, to stay by her side and grow old together]], and Rose has to decide if she can trust this Doctor. So she asks both of them what they meant to tell her two seasons earlier. [[spoiler:The Time Lord Doctor CannotSpitItOut, but the human one whispers his answer into her ear. She seems to find the answer acceptable and kisses him, accepting him.]]

** In the ''Series/StarTrekTheOriginalSeries'' episode "[[Recap/StarTrekS3E14WhomGodsDestroy Whom Gods Destroy]]", a shapeshifting madman assumes Kirk's appearance and tells Scotty to beam him back aboard. Much to his chagrin, Scotty challenges him with a [[ChessMotif three-dimensional chess move]] "Queen to Queen's level three, sir" -- to which only Kirk and Spock knew the appropriate countersign (Queen to King's level one).

* ''Series/LegendsOfTomorrow'': After some effort, Zari manages to convince Nate that she's caught in a GroundhogDayLoop. Nate says that on her following iterations, to come to him and say: [[GenreSavvy "Groundhog Day"]].
* ''Series/{{Batwoman|2019}}''. In "An Un-Birthday Present", Mouse and the Wonderland gang are holding hostages and demanding the release of Alice (formerly Beth Kane). A Beth from an alternate universe where she was never driven insane has just arrived on the scene, and tries to imitate her evil psychotic self to get Mouse to release the hostages. Unfortunately Beth has never met Alice and Mouse quickly becomes suspicious, asking, "Are there any lions or tigers about here?", the TrustPassword they used as children when hiding from [[MadDoctor Mr. Cartwright]] (the correct answer is: "It's only the Red King snoring.").

* In ''VideoGame/{{Undertale}}'', [[spoiler:if the player loads the game immediately after receiving a pacifist judgement from Sans and receives it again, he will notice that you seem to have heard his speech before; to put you to the test, he gives you a Trust Password that he's been setting up [[CrazyPrepared just in case he ever needed to verify if someone's a time traveler]]. If you load again, The Child will tell Sans the password, "I'm a [[BigStupidDoodooHead stupid doodoo butt]]," and he will, in turn, give you the ''true'' trust password that will verify, once and for all, that you're a time traveler. Load again and The Child will give Sans the second password, "I'm the legendary fartmaster," and he will, in turn, gives them the key to his room.]]

* In ''Webcomic/HomeOnTheStrange'', Tanner [[http://www.homeonthestrange.com/view.php?ID=221 sets one of these up with Izzy,]] to the latter's bemusement.

** In "Oceans Unmoving", (major spoilers), [[spoiler:it's {{inverted|trope}}. Bun-Bun can't appear himself to his past self as himself, because he knows that if he were to see someone claiming to be himself from the future, he'd figure it was a trap and kill them, expecting that if it were really him he would have expected that.]]

* In ''WesternAnimation/YoungJustice2010,'' [[FragileSpeedster Wally]] is initially the only member of the Team who knows Comicbook/{{Robin}}'s SecretIdentity. In one issue of the tie-in comic they battle Clayface and Robin is met by two Wallys; he asks them for his middle name. [[spoiler:Unfortunately for him, [[MesACrowd both]] were Clayface]].

* [[http://blogs.discovermagazine.com/notrocketscience/2012/11/08/fairy-wrens-teach-secret-passwords-to-their-unborn-chicks-to-tell-them-apart-from-cuckoo-impostors/ Some birds]] teach these to their unhatched chicks, which then use the password in their begging calls. If the parents return to their nest and do not hear the password, they'll know that the nest has likely been taken over by [[https://en.wikipedia.org/wiki/Brood_parasite brood parasites]] and will abandon the nest.

* In one episode of ''{{Series/Bones}}'', a boy is kidnapped. Booth asks the dad what password he can use so the boy will trust him during the rescue. (It turns out to be "Paladin" -- ''i.e.'' "defender of the faith", which as his boss notes is an oddly appropriate one for a Catholic FBI agent.)

** ''Series/StarTrekPicard'': The ''Titan'' is attempting to ascertain whether Captain Tuvok is a Changeling over a subspace communication. The voice result is inconclusive. Seven of Nine then references the game kal-toh, which she and Tuvok played often aboard Voyager. After Tuvok's response, she appears relieved. This, however, is a DoubleSubversion: One, because he ''is'' a Changeling, and two, because Seven's next sentence was ''another'' test, bringing up the ''Voyager'' episode "[[Recap/StarTrekVoyagerS5E7InfiniteRegress Infinite Regress]]"... which Changeling!Tuvok fails.

* "[[https://www.fanfiction.net/s/14225689/1/Multiverse-Of-Madness Multiverse of Madness]]" features a variation of this when JJ Oliver and Minh Kwan (''Film/MightyMorphinPowerRangersOnceAndFuture'') find themselves in an alternate reality with alternate versions of the original Power Rangers (''Film/PowerRangers2017''). After JJ and Minh follow this world's Rangers to the ship that serves as their version of the Command Centre, Minh reveals her morpher to the local team while assuring them that it isn't a weapon as they "only use [their] weapons for defence", quoting the original theme song and a core rule of being a Ranger.

* In the ''Fanfic/UnacceptableSitchSeries'' (specifically "Under the Milky Way Tonight"), Señor Senior, Sr. gave his attorneys a list of passwords to prove he was of sound mind and free of coercion. Specifically, any future changes to his will would include all but one of them.

* ''Film/EdgeOfTomorrow''. On being told Cage is in a GroundhogDayLoop, Dr Carter hides a hand behind his back and asks how many fingers he's holding up (two). Cage has no idea, telling Carter that this is the first time they've met. On later loops, Cage can just cut to the chase and tell Carter he's holding up two fingers to verify that he's looping in time.

* In ''Film/EdgeOfTomorrow'', Rita devises one for Cage when he first convinces her that he can time travel, allowing him to quickly convince past her in subsequent loops. She also decides to reveal her middle name "Rose" to him, probably to make it even easier for him in subsequent "runs".

* In the UsefulNotes/ColdWar mini-series ''Codename: Kyril'', "For the love of the Motherland" is a code-phrase given to Soviet [[TheMole sleeper agents]]. [=MI6=] Royston tells Sculby to use the phrase when he meets the eponymous KGB agent Kyril, to convince him he's on Kyril's side, but Kyril doesn't believe it for a second. Turns out Royston is framing Sculby as a Soviet agent (his conversation with Kyril is bugged) when Royston is actually TheMole, which the audience discovers when Royston shoots dead a KGB agent to preserve his cover, saying, "I do this for the love of the Motherland!"

* ''Film/BillAndTed'':

* In ''Literature/OonaOutOfOrder'', the titular protagonist is UnstuckInTime. Oona's first leap in time takes her to 2015. She wakes up not knowing where she is or what has happened to her. When she encounters Kenzie, she doesn't recognize him and doesn't believe him when he claims to be her 51-year-old self's personal assistant. In her mind, she is just 19 and it is 1983. Fortunately, he is prepared with anecdores from the 1982 New Year's Eve party, like how she caught the band drummer doing cocaine.

* In the ColdWar mini-series ''Codename: Kyril'', "For the love of the Motherland" is a code-phrase given to Soviet [[TheMole sleeper agents]]. [=MI6=] Royston tells Sculby to use the phrase when he meets the eponymous KGB agent Kyril, to convince him he's on Kyril's side, but Kyril doesn't believe it for a second. Turns out Royston is framing Sculby as a Soviet agent (his conversation with Kyril is bugged) when Royston is actually TheMole, which the audience discovers when Royston shoots dead a KGB agent to preserve his cover, saying, "I do this for the love of the Motherland!"

** "[[Recap/DoctorWhoS30E13JourneysEnd Journey's End]]": [[Recap/DoctorWhoS28E13Doomsday Two seasons earlier]], [[spoiler:Rose Tyler was locked in an alternate universe and separated from the Doctor, who only had the energy to send her one message to tell her he loves her. However, his energy source runs out at "Rose Tyler, I--".]] In this episode, there are [[DoppelgangerReplacementLoveInterest two Doctors]], one of which is [[spoiler:human while the other one is still a Time Lord. The human Doctor is offering, and able, to stay by her side and grow old together]], and Rose has to decide if she can trust this Doctor. So she asks both of them what they meant to tell her two seasons earlier. [[spoiler:The Time Lord Doctor CannotSpitItOut, but the human one whispers his answer into her ear. She seems to find the answer acceptable and kisses him, accepting him.]].

** According to tradition the phrase "schild en vriend" (Flemish for "shield and friend") was used during the Matins of Bruges (1302) to weed out and slaughter the members of the French garrison because the "sch" sound was hard to pronounce correctly for French speakers. (some suggest it was actually meant to be " 's gilden vriend" ("friend of the guilds"- as in "Are you a friend of the guilds?") but there's little to no proof to support this)

* Magician Creator/HarryHoudini had spent much of his later career debunking mediums and others who claimed to speak "from beyond the grave". He debunked several mediums who tried to contact his mother and made the mistake of having her address him as "Harry" (which was his stage name, when she would use his real name, Erik) or speaking in English (when she was more confident in Hungarian or Yiddish). Houdini also arranged a number of code phrases (one being a song called "Rosabelle") with his wife Bess which he promised to use if he died before her and tried to contact her after death. He died in 1926, well before Bess, and no one was ever able to deliver a message she was satisfied was genuine.

** "[[Recap/DoctorWhoS32E1TheImpossibleAstronaut The Impossible Astronaut]]": When Amy needs to get the Doctor to trust her, she tells him a detail only they would know: the Doctor's WackyCravings from their first meeting.

** "[[Recap/DoctorWho60thASWildBlueYonder Wild Blue Yonder]]": In the climax of the episode, Donna and her [[EldritchAbomination Not-Thing]] clone both try to convince the Doctor that they are the real Donna, which is difficult since the Not-Thing can read minds and knows everything Donna knows. The Doctor asks them what the name of Donna's old choir teacher is ("Mrs. Beans"), and then asks why that is funny. One Donna tries to logically explain, the other replies "It just is," and the Doctor pulls the second one in. [[spoiler:It turns out that was the wrong one. The Doctor only realizes his mistake when the TARDIS scans the fake Donna and shows him that her arms are a fraction of a millimeter too long, and he has to scramble to eject her and grab the real Donna.]]

** "[[Recap/DoctorWho60thASWildBlueYonder Wild Blue Yonder]]": In the climax of the episode, Donna and her [[EldritchAbomination Not]]-Thing clone both try to convince the Doctor that they are the real Donna, which is difficult since the Not-Thing can read minds and knows everything Donna knows. The Doctor asks them what the name of Donna's old choir teacher is ("Mrs. Beans"), and then asks why that is funny. One Donna tries to logically explain, the other replies "It just is," and the Doctor pulls the second one in. [[spoiler:It turns out that was the wrong one. The Doctor only realizes his mistake when the TARDIS scans the fake Donna and shows him that her arms are a fraction of a millimeter too long, and he has to scramble to eject her and grab the real Donna.]]

** "[[Recap/DoctorWho60thASWildBlueYonder Wild Blue Yonder]]": In the climax of the episode, Donna and her Not-Thing clone both try to convince the Doctor that they are the real Donna, which is difficult since the Not-Thing can read minds and knows everything Donna knows. The Doctor asks them what the name of Donna's old choir teacher is ("Mrs. Beans"), and then asks why that is funny. One Donna tries to logically explain, the other replies "It just is," and the Doctor pulls the second one in. [[spoiler:It turns out that was the wrong one. The Doctor only realizes his mistake when the TARDIS scans the fake Donna and shows him that her arms are a fraction of a millimeter too long, and he has to scramble to eject her and grab the real Donna.]]

** "[[Recap/DoctorWho60thASWildBlueYonder Wild Blue Yonder]]": In the climax of the episode, Donna and her Not-Thing clone both try to convince the Doctor that they are the real Donna, which is difficult since the Not-Thing can read minds and knows everything Donna knows. The Doctor asks them what the name of Donna's old choir teacher is ("Mrs. Beans"), and then asks why that is funny. One Donna tries to logically explain, the other replies "It just is," and the Doctor pulls the second one in. [[spoiler:It turns out that was the wrong one. The Doctor only realizes his mistake when the TARDIS scans the fake Donna and shows him that her arms are a fraction of a millimeter too long, and has to scramble to eject her and grab the real Donna.]]

** "[[Recap/Recap/DoctorWho60thASWildBlueYonder Wild Blue Yonder]]": In the climax of the episode, Donna and her Not-Thing clone both try to convince the Doctor that they are the real Donna, which is difficult since the Not-Thing can read minds and knows everything Donna knows. The Doctor asks them what the name of Donna's old choir teacher is ("Mrs. Beans"), and then asks why that is funny. One Donna tries to logically explain, the other replies "It just is," and the Doctor pulls the second one in. [[spoiler:It turns out that was the wrong one. The Doctor only realizes his mistake when the TARDIS scans the fake Donna and shows him that her arms are a fraction of a millimeter too long, and has to scramble to eject her and grab the real Donna.]]

* In Garth Nix's Literature/OldKingdom series, the line of Abhorsens has the ArcWords "Does the walker choose the path, or the path the walker?" When apparent heir Samuel doesn't recognize the phrase, he makes it clear he's completely unprepared to take up the mantle.

* In Alistair Maclean's spy novel ''Literature/TheDarkCrusader'' (published in the USA as ''The Black Shrike''), the hero includes the nonsense word ''Bilex'' in all communications with headquarters to show that the message is genuine and not written under duress. After he is captured, the enemy claim to have sent a fake message that all is well, which presumably would not include the codeword. The twist is that [[spoiler:the hero's boss is actually in league with the enemy, something he realises when his boss takes no action in response to an obviously fake message... which was probably never actually sent anyway]].
* ''The Brotherhood of the Rose'' by David Morrell. The CIA are following Saul until he makes contact with his surrogate brother Chris and they can both be killed. When Saul sets up the meeting, an underling urges spymaster Elliot to let them grab Saul and sweat the meeting place out of him. Elliot turns this idea down, pointing out that Chris and Saul have known each other since they were children and have codes and passwords dating back to then, so they've no way of being sure that Saul couldn't pass on a hidden warning.

* On ''Series/{{Cursed}}'', if trying to figure out if someone is a Fey, a member of the Fey will greet them with the phrase "Born in the dawn..." to which they are supposed to reply with "...to pass in the twilight." The full phrase, as spoken by Gawain and Squirrel, is apparently "A knight of the Fey is one with the land, as enduring as the Great River and as true as Arawn's bow. We are born in the dawn, to pass in the twilight."