Alexander D Agapeyeff Popular Books
Alexander D Agapeyeff Biography & Facts
The D'Agapeyeff cipher is an unsolved cipher that appears in the first edition of Codes and Ciphers, an elementary book on cryptography published by the Russian-born English cryptographer and cartographer Alexander D'Agapeyeff in 1939. Offered as a "challenge cipher" at the end of the book, the ciphertext is: 75628 28591 62916 48164 91748 58464 74748 28483 81638 18174 74826 26475 83828 49175 74658 37575 75936 36565 81638 17585 75756 46282 92857 46382 75748 38165 81848 56485 64858 56382 72628 36281 81728 16463 75828 16483 63828 58163 63630 47481 91918 46385 84656 48565 62946 26285 91859 17491 72756 46575 71658 36264 74818 28462 82649 18193 65626 48484 91838 57491 81657 27483 83858 28364 62726 26562 83759 27263 82827 27283 82858 47582 81837 28462 82837 58164 75748 58162 92000 It was not included in later editions, and D'Agapeyeff is said to have admitted later to having forgotten how he had encrypted it. Use of nulls in ciphertext It is possible that not all the ciphertext characters are used in decryption and that some characters are nulls. Evidence for this is given by the author on p. 111 of the text under the sub-section heading Military Codes and Ciphers: "The cipher is of course easily made out, but if every third, fourth, or fifth letter, as may be previously arranged, is a dummy inserted after a message has been put into cipher, it is then extremely difficult to decipher unless you are in the secret." While the index of coincidence for the D'Agapeyeff cipher is 1.812 when taken in pairs horizontally (e.g., '75' '62' '82'), the letter frequency distribution is too flat for a 196 character message written in English. Additionally, D'Agapeyeff left two ciphers for the reader to solve. Each are approximately 100 characters in length and have an index of coincidence much higher than what is expected for English plaintext. Use of Polybius square methods in Codes and Ciphers The structure of the D'Agapeyeff Cipher has similarities to the Polybius square, which the author used as examples in his book. He explicitly solves an example of a Polybius square based cipher from a friend in his cryptanalysis section of the book. This worked example consisted of 178 characters: CDDBC ECBCE BBEBD ABCCB BDBAB CCDCD BCDDE CAECB DDDAA CABCE AABDE BCEDC BCCDA EBDCB AAEAB ECDDB DCCEC EEABD ADEAD CAADE ACABD CBDCB AABDC ACEDC BABCD DCDBD DCBEB CDCBE BCAAB DACCD DBBBC EAACD BDCDD BCEDC AECAC EDC When deciphered with a Polybius square, the plaintext of this exercise contains a mistake (based on mis-encoding "E" as "BE" rather than "CE"), but reads: "THE NEW PLAN OF ATTACK INCLUDES OPERATIONS BY THREE BOMBER SQUADRONS OVER FACTORY ARYA [AREA] SOUTHWEST OF THE RIVER" References Shulman, David (nom: Ab Struse). "The D'Agapeyeff Cryptogram: A Challenge", The Cryptogram, April/May 1952: 39-40, 46. Shulman, David (nom: Ab Struse). "D'Agapeyeff Cipher: Postscript", The Cryptogram, March/April 1959: 80-81. Barker, Wayne G (1978). "The Unsolved D'Agapeyeff Cipher", Cryptologia, 2(2): 144-147 List of famous unsolved codes, maintained by cryptographer Elonka Dunin D'Agapeyeff, Alexander. Codes and Ciphers, 1939, Oxford University Press, p. 158 External links Description of properties and potential decryption strategies for D'Agapeyeff cipher by Robert Matthews Another approach to decryption by Nick Pelling Discussion of possible causes of failure to solve D'Agapeyeff cipher, at the American Cryptogram Association website. Discover the Alexander D Agapeyeff popular books. Find the top 100 most popular Alexander D Agapeyeff books.
Best Seller Alexander D Agapeyeff Books of 2024
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Pretty Little Lies
Ivy ThornFour years ago, Nicolo Marchetti took my innocence. But he left me with something else Nicolo almost took everything from me. My virginity, my reputation, and very nearly my future...
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Alpha
Sybil BartelBillionaire. Mercenary. Navy SEAL. The Teams trained me to be a killer. War taught me to be ruthless. Then an illfated mission proved I was human. Combat wounded, cut loose by the ...
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His Girl Next Door
Khardine GrayFrom USA Today Bestselling author Khardine Gray comes a sizzling hot single dad romance you won't want to miss. No strings attached fun with the ubergorgeous single d...
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Becoming Lady Dalton
Carrie LomaxA dance of desire and deceit... In the glittering world of London's ton, Mrs. Viola Cartwright revels in her newfound freedom as a lady of leisureuntil a series of jewel theft...
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Noxious
Lexy TimmsStop setting yourself on fire to keep someone else warm. Brady and Levi have been together since high school, since before he became famous and started thinking only about himself....
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The Adventures of Sherlock Holmes
Arthur Conan DoyleAn Apple Books Classic You get not one, not two, but 25 gripping mysteries in Arthur Conan Doyle’s first of five collections of Sherlock Holmes short stories. Follow the brilliant ...
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Escape, A New Life
David J AntocciTo save herself, she had to lose everything. Trapped in a tropical paradise with no memory of how she got there, Abby is thrust into a fight for her life. Hunted by a madman, and c...
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A Green Kind of Witch
Sierra CrossCinderella crossed with Mean Girls.   That's what Hazel's daily existence feels like. Born to a family of elegant yet shallow Beige Witches, seventeen y...
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Whiskey Girl
Melissa BelleThey'll do anything for each other…except commit. Logan Wild isn’t just the hottest broncriding cowboy in Texas. He’s also my best friendwith benefits. And that’s all we’ll ev...
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The Four Loves
C. S. LewisThe Four Loves summarizes four kinds of human loveaffection, friendship, erotic love, and the love of God. Masterful without being magisterial, this book's wise, gentle, candi...
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Meditations
Emperor of Rome Marcus AureliusMeditations is a series of personal writings by Marcus Aurelius, Roman Emperor 161–180 CE, setting forth his ideas on Stoic philosophy.
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A Christmas Carol
Charles DickensAn Apple Books Classic edition. It’s Christmas Eve in Victorian England. While some families don’t know where their next meal will come from, Ebenezer Scrooge sits in his large hom...
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Death at Hazel House
Betty Rowlands‘Riveting, can't put it down! I love this story… a wonderfully twisted tale of a crime that has more twists than I thought possible... fantastic.’ Goodreads Reviewer, 5 stars ...
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Law of Attraction
Jordan HollisHow to Finally Overcome the Hurdles of Manifesting Proven, effective and enjoyable ways to help you manifest faster… Right now, think of something that makes you successful. If you...
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Dracula
Bram StokerAn Apple Books Classic edition. Few characters have seized readers’ imaginations quite like Count Dracula of Transylvania, the hero of Bram Stoker’s classic. The 1897 novel put vam...
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The Odyssey
HomerAn Apple Books Classic edition. Homer’s eighthcentury epic poem is a companion to The Iliad . It tells the story of Odysseus, who journeys by ship for 10 years after the Trojan War...
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Bewitching a Highlander
Roma CordonDefying all for the love of a bewitching lass. Breena MacRae, a healer from Skye with a touch of witchery in her blood, embarks on a dangerous search for her missing father. She ar...
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The Art of War
Sun TzuAn Apple Books Classic edition. It’s believed that Sun Tzu wrote this Chinese military primer during the 5th century BChundreds of years before the Bible. The book’s 13 chapters ex...
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Teased by Fire
Molly O'HareFrom USA Today bestselling author Molly O’Hare comes an enemiestolovers, older brother’s best friend, romantic comedy with a curvy, antisocial, supernaturalobsessed, allyearround h...
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Little Women
Louisa May AlcottAn Apple Books Classic edition. Meet the Marches! Louisa May Alcott’s classic introduces us to four unforgettable sisters: beautiful Meg, tomboyish Jo, delicate Beth, and Amy, the ...
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Get Lucky
Lila MonroeFall for the hot and hilarious romcom spin on 'The Hangover', perfect for fans of Tessa Bailey, Ali Hazelwood, and Emily Henry! What happens when you wake up in a hotel s...
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Hot Off the Press
Lexy Timms"This is what really happened… reported by a free press, for a free people…" Wes Shaw leads a secret double life. As the secret owner of a billion dollar newspap...
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Never Enough
Lexy TimmsBe good enough never is... Anthony Accardi is a man on a mission: make his father's watch company a success while bringing in millions of dollars. To do that, he needs an assi...
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Awaken Me
Jenna JacobHe was more than a ghost haunting my dreams…he was real. By day, I’m Julianna Garrett …a prim, proper accountant. By night, I’m tormented by dreams of an alpha, ambereyed Adonis wh...
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The Next Girl
Carla KovachIF YOU ONLY READ ONE BOOK THIS YEAR, MAKE IT THE NEXT GIRL... You thought he’d come to save you. You were wrong. ‘ Absolutely the best thriller I’ve read this year! ’ Goodreads Rev...
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Wuthering Heights
Emily BrontëAn Apple Books Classic edition. If you’ve only ever seen Wuthering Heights on screen, you may have an image of Catherine and Heathcliff as the ultimate starcrossed lovers. But that...
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Masters of Restraint
Ines JohnsonMy new boss is good at giving orders. But his latest demand is NSFW. Especially when his two business partners want in on our deal. My new boss My boss’s boss Their investor &#...
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My Paper Heart
Magan VernonOne piece of paper can change everything After my parents received the letter I failed out of college, they didn't ask questions. They just sent me to work for my great aunt i...
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Peace on Earth
Maia RossCrime never takes a holiday. Why should Irma? Irma Abercrombie is an energetic retiree with a shadowy past, a mean right hook, and a profound love of Christmas. Surrounded by seaso...
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The Target
Lexy TimmsWhen you seek revenge be sure to dig two graves… Revenge was the only thing I had going for me. It kept me awake at night and drove me into desperate situations in dive bars across...
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The Cupcake Cottage
Jean OramNHL player Maverick Blades could fall in love with anyone... But he had to fall for a woman who falls under the Bro Code as untouchablehis best friend’s beautiful ex, DaisyMae Ray....
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Teach Me
Cassandra DeanFrom awardwinning author Cassandra Dean comes a tale where lessons of pleasure between a curious, sunshine widow and a dissolute, grumpy earl leads to passion and allconsuming love...
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His Own Heaven
Jennie KewWinner of the 2021 Passionate Plume Award for BDSM Romance Finalist in the 2021 Stiletto Contest for Contemporary Romance He taught her to trust, she taught him to love. Lucy Bar...
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Inception of Gold
Lexy TimmsThings are not as bad as they seem. They are worse. Being the personal assistant to a narcissistic actress who just happens to own the key to my family's undoing isn't ex...
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The Count of Monte Cristo
Alexandre DumasAn Apple Books Classic edition. Alexandre Dumas’ classic paints a portrait of Edmond Dantès, a dark and calculating man who is willing to wait years to exact his perfect plan for r...
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Become A Better Version of Yourself
Ben LeightonThis ebook contains golden nuggets on how to motivate, inspire and improve your current situation. It encompasses the holistic view of self improvement from mental& emotion...
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A Bookshop to Die For
M.P. BlackDitching her fiancé at the altar, Alice Hartford bolts to her childhood hometown to reconnect with the last, happy remnant of her past: her mom's old bookstore. But the bookst...
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Salvation
Meghan O'FlynnIf you like mouthy detectives, serial killers, and suspenseful mysteries that don't quit, this chilling and actionpacked hardboiled detective series has you covered! Try this ...
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Pride and Prejudice
Jane AustenAn Apple Books Classic edition. Jane Austen’s beloved classic opens with this witty and very memorable line: “It is a truth universally acknowledged, that a single man in possessio...
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Think and Grow Rich
Greg Habstritt & Napoleon HillThink and Grow Rich is one of the most popular success book of alltime, having sold more than 60 million copies since it was first published more than 70...
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The Icing on the Cake
Linda SeedShe’s a baker without a kitchen. He’s got a double oven to spare. It’s a recipe for success, until his mother starts stirring up trouble … Cassie Jordan has a sweet dream to open a...
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Just Me
Lexy TimmsWe all need somewhere where we feel safe… After leaving her abusive husband, Katherine Marshall is out on her own for the first time. She's hopped from city to city to avoid t...
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Coffee Girl
Sophie SinclairMackenzie "Kiki" Forbes finds herself in a pickle. Either become her snarky sister's nanny, or move halfway across the country to work as assistanttothestylist of a ...
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The Stoic Mind
Addy Osmani & GoLimitlesssDiscover the timeless wisdom of Stoicism in a modern context with "The Stoic Mind," an enlightening visual guide by Addy Osmani and GoLimitlesss. This rich exploration co...
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Good Guy
Kate MeaderHe's a Special Forces veteran making his pro hockey debut. She's a dogged sports reporter determined to get a scoop. She's also his best friend's widow . . . Fa...
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The Three Little Pigs
Mark LeskyClassic fairy tales, legends and folk stories in short version without violence retold with lovely illustrations in simple language. Perfect for reading aloud to small chi...
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The Honeymoon Homicide
J. R. Mathis & Susan MathisEnjoy this SmallTown Murder Mystery Featuring A Unique Sleuthing Couple I'm Father Tom Greer, a Catholic Priest in a smalltown parish who never expected this . . . When I came...
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The Wonderful Wizard of Oz
L. Frank BaumAn Apple Books Classic edition. You’ve seen the iconic 1939 movie, but do you know about the talking field mice, the Winkies, and the Witch of the North that appear in the original...
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Caught Up with the Captain
Kait NolanCan a retired naval commander and the love he left behind overcome a 34yearold secret to find their way to a second chance? Captain Mitchell Greyson is a man who believes in duty. ...
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Nothing to Hide
Scarlett FinnPrize of a lifetime: travel the world with a celebrity billionaire. Come to LA with us, Roxie… It will be so much fun! We have tickets for a latenight talk show! What could possibl...