History Main / PublicSecretMessage

* [[http://lisdead.blogspot.com/ LIS_DEAD]] is seemingly an {{inversion}}; it's encrypted and secret to nobody '''except''' for a certain mysterious 'Him'

* In ''{{Replay}}'', by Ken Grimwood, in one loop, Jeff and Pam use ads with various loop-derived future references to try to make contact with other replayers.

Compare / Contrast SarcasticConfession, HiddenInPlainSight, OvertRendezvous.

* A RealLife instance (several, actually): GeneRoddenberry had served in WorldWarII with a man named Kim Noonien Singh. They lost touch after the war. Roddenberry named two characters after Singh, hoping to attract his attention -- Khan Noonien Singh in the "Space Seed" episode of ''StarTrekTheOriginalSeries'' (and ''StarTrekII''); and Noonien Soongh, Data's creator in ''StarTrekTheOriginalSeries''.

* In Orson Scott Card's "Shadow of the Hegemon" when Petra and Bean communicate by starting an e-mail signature meme: an image file of a dragon with a coded message in it and the words "Share this dragon / If you do / Lucky end for / Them and you", which reference the Dragon Army and Ender Wiggin.

* In ''[[EndersGame Shadow of the Hegemon]]'', a captured Petra creates a "luck dragon" image to attach to her emails that contains a hidden code. While it seems innocuous to her captors (and even [[MemeticMutation catches on with the world at large]]), "Dragon" was the codename of Ender's jeesh (army or group) in Battle School, so she hopes any free members of the jeesh, including Bean and Ender, will notice and decode the message.

* In PhilipKDick's ''Radio Free Albemuth'' and its more polished rewrite ''{{VALIS}}'', a subliminal message is sent to the public in the form of song lyrics so that the government won't intercept it but those who know the truth will be able to spread the message.

* In PhilipKDick's ''Radio Free Albemuth'' and its more polished rewrite {{VALIS}}, a subliminal message is sent to the public in the form of song lyrics so that the government won't intercept it but those who know the truth will be able to spread the message.

Alice needs to send a message to Bob without Carol overhearing. Unfortunately for Alice, she can't simply meet with Bob in private to discuss it, and sending a private message is either physically impossible or would arouse too many suspicions. The solution? Send a message to everyone, but encode, encrypt, or word it in a way that only Bob will understand the message. Alice might disguise the message in such a way that Carol will think it's an relatively innocent item, such as an advertisement (Wikipedia lists this technique as "[[http://en.wikipedia.org/wiki/Steganography Steganography]]"), word it so that everyone but Bob will misinterpret the meaning, or simply make the message so hard to decode that only Bob could do it.

* In ''MenInBlack'', Agent K explains that tabloids, which are assumed to be hoaxes by {{muggles}}, are in fact based on true events behind TheMasquerade (since tabloids have less WeirdnessCensor than "serious" newspapers). Later, when [[spoiler:agent K retires]], Agent J notices an article with [[spoiler: Agent K's photo and an article about a postal worker who returned to his old job after years in a coma.]], revealing [[spoiler: Agent K]]'s fate, which then becomes a major plot point in the second film.

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* In the fifth ''HarryPotter'' book, Harry alerts Snape while making it possible to convince Umbridge he was shouting gibberish, by yelling "He's got Padfoot at the place where it's hidden!" to the entire room. Snape understands that "Padfoot" was Sirius' old nickname and "the place" was a location that Snape knows Harry's been seeing in his dreams.

* Agatha Christie wrote of a spy who was behind enemy lines and managed to find a really crucial piece of information but had no way of passing it on, so in the end he sacrificed himself, committing a series of murders and getting convicted - it seemed like random acts of violence but those who knew he was a spy figured that the victims' personal data was used as a code.

* In an episode of the Adam West ''{{Batman}}'', Batman talked to one of the villains over a broadcast radio station, but requested that all other citizens of Gotham switch off to avoid hearing his private message. Naturally they obliged.

* On {{Chuck}}, [[spoiler:Steven Bartowski]] provides Ellie Bartowski with a method for contacting him through coded messages in the personal ads.

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* This [[http://xkcd.com/370/ XKCD]] makes fun of the public messages in Redwall.

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* In ''TheSimpsons'' episode, "My Mother the Carjacker", Mona Simpson encodes secret messages to her son in the Newspaper, on food articles, using the first letter from each word.

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Compare / Contrast SarcasticConfession, HiddenInPlainSight.

* In the ''Series/DoctorWho'' episode "Blink", the Doctor records message that a DVD publisher he befriends adds as a "deleted scene" on some very specific [=DVDs=] (corresponding to the entire DVD collection of one character) decades later. It makes no sense whatsoever, until late in the episode where it's revealed to be TheTapeKnewYouWouldSayThat: The character's reactions to the scene form a perfectly cohesive conversation with the Doctor (who has a transcript of her reactions) regarding the TARDIS and the Weeping Angels.

* In the DoctorWho episode "Blink", The Doctor inserts a recorded message as a "deleted scene" on some very specific DVDs (corresponding to the entire DVD collection of one character). It makes no sense whatsoever, until late in the episode where it's revealed to be TheTapeKnewYouWouldSayThat: The character's reactions to the scene form a perfectly cohesive conversation with The Doctor (who has a transcript of her reactions) regarding the Tardis and the Weeping Angels.
** Again DoctorWho, ''Bad Wolf'' was used as one.

* One of the features of "public key encryption" is that you can publish one key, letting anyone send you a message that no one without the other key can decipher. Or conversely, you can publish the decryption key so that everyone can read your messages knowing they could only have come from you.

* ''Webcomic/GirlGenius'': [[http://www.girlgeniusonline.com/comic.php?date=20050620 here]] a bunch of [[SuperSoldier Jagers]] are posing and ChewingTheScenery, probably loud enough to hear for not only a few panicked bystanders, but half of the town. Dimo's first phrase, however, had a very specific meaning, which [[http://www.girlgeniusonline.com/comic.php?date=20050624 the only intended listener recognized]] immediately (and was somewhat shocked). And it's something they say openly only when they are ''sure'' no outsider can possibly overhear.

* In ''MenInBlack'', Agent K explains that tabloids, which are assumed to be fictional by {{muggles}}, are in fact based on true events behind TheMasquerade. Later, when [[spoiler: agent K retires]], Agent J notices an article with [[spoiler: Agent K's photo and an article about a postal worker who returned to his old job after years in a coma.]], revealing [[spoiler: Agent K]]'s fate, which then becomes a major plot point in the second film.

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* One of the features of "public key encryption" is that you can publish one key, letting anyone send you a message that no one without the other key can decipher. Or conversely, you can publish the decryption key so that everyone can read your messages knowing they could only have come from you.

* In ''EndOfEternity'', a stranded time traveller publishes an advertisement in a newspaper containing a picture of a mushroom and the phrase:

* In ''The Anubis Gates'' by Tim Powers, time travelers in the early 19th century get each other's attentions on busy city streets by whistling {{Beatles}} songs.

* In ''The Anubis Gates'' by Tim Powers, time travelers in the early 19th century get each other's attentions on busy city streets by whistling Beatles songs.

* In ''RedDragon'', Hannibal Lecter places a personal ad filled with Bible verse numbers in a tabloid as a coded message (the numbers refer to the nth letter on the xth page of his edition of ''The Joy of Cooking'') to Francis Dolarhyde. The FBI decrypts it, and realizes that it told Dolarhyde where Will Graham lives; they send Dolarhyde another message to lure him into a trap, but he recognizes it for whot it is.