Solution Explained: Cyrillic Projector

Overview: This is a clear, but slightly technical overview of the EXACT SOLUTION needed to solve the Cyrillic projector. You can find more information about the corrected Kryptos solutions here.

Cyrillic projector: This cipher has previously been solved by Elonka Dunin and John B Wilson. The information they provided was incredibly helpful [And I can not thank you both enough], though keen eyes will notice some variations in their approach and some explanations are missing. This overview properly ‘combines’ the two techniques in order to reach an output. Because the Cyrillic projector is not well documented in its solutions as other ciphers, I have attempted to make this as clear as possible for individuals looking to investigate Kryptos and K4 further.

Cipher text:

ЛТФЕЮТФЯЙЯМПХЦФАЧНЩПВБГЖЧСКЬГГЛЗДЭЙПЪКХСЙРЭАФНФПЩВПЕЦРДФАЩШТКСХСЧЫУХХЕЮКУМЛЕЧЛЫТОБНЕЯЖЖИЬНЭЗЩЦРЛЫБПНФОИИАБЬПИКЛЕУРЫСМЪШЛЛБХМХЛЖШРАЩРЙЛПЕООЙЙВЦИЪЛБХЦРЫЧСКАРСРВЯЭФКЮФРЮМОЯЗОЛОДЭШРЗУДХМАЭХОЙГЙЮФМЩХХСВИИЗХАГЙЯЬПСИБРРШОМКТСУЯГХУЬЛЕУРЫСМЪШСППЯЯЦШУШАЦЧПИМШНРБЧРЯЫМИУРАДФАИЮЙЫЦЯЛОНУФЖОФШХФЖСБВЪЧДЦСФБМДЭШРЗУДХУРБШТОКЩЪМХПОТОХОЩЧЖАЦДЩРАЮГОЙВРБГЮБЗГЕЖРЙЛПЕООЙЙВЦНЗПГФЦЗАИВЯЮФЛЪЦХСЧЫШЬБЕОМЩШЖТЭДЙОТТФХПРПЛОДЭЩРЗУДХКПГФОЦБЩЪММЭКЧЕРЛМКЪЦЦЗЩЛФЦЧЪЩКВНФАЕСДПТДФПРЯЙКЮНХВЦБЮЕИСЧЯЧЦХМЖЛСПРЧУЛЭШЖЫИИMEDUSAИНХЕЗЛЧЗРЗЙКЛППЕВЛЧСХЦЫОЙВРБУДХСВЪГЖЧСКАРСРВЯЭФРЩФЯЦЩПЪЗЫТФОЙЙУСДТЮТВСБРХСПБЩЛШКУВЙЙГЗЙАЧЛЬРЙЭМДЧЧРЬСТНКЙЕКДОБЖБЛШИЫЙБЙИДРРЦХОЩЖВЪКБЧКЖНФПШЦЗУЙДЯГАЧЙКУЗФЕЦИЯИЙФЭБЛСДТГЗШРЖЕДФЩЖЙЯНБООЬШФПЮКЗЦУДИНХЕОХПОЙАХДЭСБЩЙЖЭШВЪОДЩВУСЛМЩГЖШУДИГЛЕШКПУУЕЧДЛСУЦЮТЮНХЪПБУПРЬГИУСБЙЙПЮГАФФЕШБФБМЙПИМЪЮКЩХХТНФЩШПЕЯБЧККЩВЙЩЗЛЮСВЮЙКУКФСЫТЫСВЛСЛЬЗУЦИКЩДРСУРЗХРФЙРЭМРХФЛКФАЙЙКУАЛЩГМЙЖШЪЙЬЩКФНФИДЙРФГКУКАЯЙОУМАТЭТЦКВЕЖОЙИДЦДКГЩФЕЖБЮХЛЕССЭСНЩЩХПОЬДЖЙЙЗГЕИТЙМАШЙЙУМФСЫТЫСВСИДСДРБФНУОРУШТБЗПЪДЗЯЫААЧКУМАЯХТМЦРИЦЗЩЛЛЕУУПФЖТЭДУХРШЙОРБЭЦЙОПЙЛЪЙТЧШЙАФНПШФЭМБЩЪЖТПДЛРШБШБЧРЖЫМНЧЗЫТЙЖЪСМЪЧДХКЛНЦПЗХРФЙРЭМРХФМЫБВЪЧБШЕФБЖТЩВВЪУБЧКЖАЦПЫГШАМИПРЙЪГОЦКЙГРЛЮБУСПБЮРРХФТЫХЖТГИЙКАФМТНКЙФФНЦЙЫСЧБШЕФБЖБЛСВТЧРЫЙПТМБОЙМСГУМБПЪЦРЙРАЪХКЫХАДГОЩГДЦСТМСГЪЮБЭМЙЩГЯЛОЬЦЧШЮСФЕЖБЮХЛЕЙЬЩХШШГОЭШВЕХОЩЖРЮКТПШРАЧТЛБХМЦЯСБЛЬНРГПРУТБЭШВЕСМЫЗФЮЙАЯЗХУФОНСВЩГМЫБВСЮБШСВЦПТЪТХСЙРЭАФЭФЙЪФРЯЙРУФРФГРДЭЙЬФЗЩЗАТЧДЛСЖТУЛПЖВЪКБЧКЖТГГЙУАШЙДПДРЬЩЗЩГРШМРПОЖЫФЕЛКПНЙРЯЫААЧКУМРФХТМЦРИЦЗЩДРШЖДРЗПЪВНЭОЖНФЙЭОЖШФНЙРЙЪХЛШКХЪПБЭХФЬХОЩГРЖМОЯЗХВЮБЧТЧЭЖЙПЭАБЙИДХХФЩНЩДПВЧОПРПЪЙАПОАТГЦПЛФБШТЧТЙФНПЮЦСЮЙКУАХФЛТБКХВРДНСФВКАПРПЛЫГЙХРФЙОАЗПЪЙЛЭСБЕФМЙХПЛЫЬЩХШШГОЭШВЦУКГ

Tableau side text:

ТЕНЬАБВГДЖЗИЙКЛМОПРСУФХШЦЧЩЪЫЭЮЯТЕН
ЕНЬАБВГДЖЗИЙКЛМОПРСУФХШЦЧЩЪЫЭЮЯТЕНЬ
НЬАБВГДЖЗИЙКЛМОПРСУФХШЦЧЩЪЫЭЮЯТЕНЬА
ЬАБВГДЖЗИЙКЛМОПРСУФХШЦЧЩЪЫЭЮЯТЕНЬАБ
АБВГДЖЗИЙКЛМОПРСУФХШЦЧЩЪЫЭЮЯТЕНЬАБВ
БВГДЖЗИЙКЛМОПРСУФХШЦЧЩЪЫЭЮЯТЕНЬАБВГ
ВГДЖЗИЙКЛМОПРСУФХШЦЧЩЪЫЭЮЯТЕНЬАБВГД
ГДЖЗИЙКЛМОПРСУФХШЦЧЩЪЫЭЮЯТЕНЬАБВГДЖ
ДЖЗИЙКЛМОПРСУФХШЦЧЩЪЫЭЮЯТЕНЬАБВГДЖЗ
ЖЗИЙКЛМОПРСУФХШЦЧЩЪЫЭЮЯТЕНЬАБВГДЖЗИ
ЗИЙКЛМОПРСУФХШЦЧЩЪЫЭЮЯТЕНЬАБВГДЖЗИЙ
ИЙКЛМОПРСУФХШЦЧЩЪЫЭЮЯТЕНЬАБВГДЖЗИЙК
ЙКЛМОПРСУФХШЦЧЩЪЫЭЮЯТЕНЬАБВГДЖЗИЙКЛ
КЛМОПРСУФХШЦЧЩЪЫЭЮЯТЕНЬАБВГДЖЗИЙКЛМ
ЛМОПРСУФХШЦЧЩЪЫЭЮЯТЕНЬАБВГДЖЗИЙКЛМО
МОПРСУФХШЦЧЩЪЫЭЮЯТЕНЬАБВГДЖЗИЙКЛМОП

ОПРСУФХШЦЧЩЪЫЭЮЯТЕНЬАБВГДЖЗИЙКЛМОПР
ПРСУФХШЦЧЩЪЫЭЮЯТЕНЬАБВГДЖЗИЙКЛМОПРС
РСУФХШЦЧЩЪЫЭЮЯТЕНЬАБВГДЖЗИЙКЛМОПРСУ
СУФХШЦЧЩЪЫЭЮЯТЕНЬАБВГДЖЗИЙКЛМОПРСУФ
УФХШЦЧЩЪЫЭЮЯТЕНЬАБВГДЖЗИЙКЛМОПРСУФХ
ФХШЦЧЩЪЫЭЮЯТЕНЬАБВГДЖЗИЙКЛМОПРСУФХШ
ХШЦЧЩЪЫЭЮЯТЕНЬАБВГДЖЗИЙКЛМОПРСУФХШЦ
ШЦЧЩЪЫЭЮЯТЕНЬАБВГДЖЗИЙКЛМОПРСУФХШЦЧ
ЦЧЩЪЫЭЮЯТЕНЬАБВГДЖЗИЙКЛМОПРСУФХШЦЧЩ
ЧЩЪЫЭЮЯТЕНЬАБВГДЖЗИЙКЛМОПРСУФХШЦЧЩЪ
ЩЪЫЭЮЯТЕНЬАБВГДЖЗИЙКЛМОПРСУФХШЦЧЩЪЫ
ЪЫЭЮЯТЕНЬАБВГДЖЗИЙКЛМОПРСУФХШЦЧЩЪЫЭ
ЫЭЮЯТЕНЬАБВГДЖЗИЙКЛМОПРСУФХШЦЧЩЪЫЭЮ
ЭЮЯТЕНЬАБВГДЖЗИЙКЛМОПРСУФХШЦЧЩЪЫЭЮЯ
ЮЯТЕНЬАБВГДЖЗИЙКЛМОПРСУФХШЦЧЩЪЫЭЮЯТ
ЯТЕНЬАБВГДЖЗИЙКЛМОПРСУФХШЦЧЩЪЫЭЮЯТЕ

Decrypted Text:

B Ы C O Ч A Й Ъ И M И C К У C C T B O M B T A Й H O Й P A З B E Д К E C П И T A E T C Я C П O C O Б H O C T Ь P A З P A Б O T A T Ь И C T O Ч H И К К O T O P Ы M T Ы Б У Д E Ш Ь B C E Ц E Л O P A H П O P Я Ж A T Ь C Я И К O H T P O Л И P O B A T Ь П O Э T O C У T A Й H O Й P A З B E Д Ы B A T E Л Ь H O Й C Л У Ж Б Ы К O H T P O Л И P У E M Ы Й И C T O Ч H И К К A К П P A B И Л O П O C T A Я Л Я E T C A M У Ю H A Д E Ж H У Э И H Ф O P M A Ц И Ю К O H T P O Л И P У E M Ы M C Ч И T A E T C Я К У П Л E H H Ы Й И Л И H A X O Д Я Щ И Й C Я B Л Ю Б O Й Д P У Г O Й З A B И T И M O C T И И C T O Ч H И К П O T P A Д И Ц И И Ц E Л Ь Э П P O Ф E C C И O H A Л A P A Б O T A Ю

Accounting for intentional spelling errors:

BЫCOЧAЙЪИM ИCКУCCTBOM B TAЙHOЙ PAЗBEДКE CПИTAETCЯ CПOCOБHOCTЬ PAЗPAБOTATЬ ИCTOЧHИК КOTOPЫM TЫ БУДEШЬ BCEЦEЛO PAHПOPЯЖATЬCЯ И КOHTPOЛИPOBATЬ ПOЭTOCУ TAЙHOЙ PAЗBEДЫBATEЛЬHOЙ CЛУЖБЫ КOHTPOЛИPУEMЫЙ ИCTOЧHИК КAК ПPABИЛO ПOCTAЯЛЯET CAMУЮ HAДEЖHУЭ ИHФOPMAЦИЮ КOHTPOЛИPУEMЫM CЧИTAETCЯ КУПЛEHHЫЙ ИЛИ HAXOДЯЩИЙCЯ B ЛЮБOЙ ДPУГOЙ ЗABИTИMOCTИ ИCTOЧHИК ПO TPAДИЦИИ ЦEЛЬЭ ПPOФECCИOHAЛA . . .

Translated Decoded Text:

The highest skill of the secret service is the ability to develop a source, which you will handle and control completely so that the source supplies, as a rule, the most reliable information. A controllable source is a source that is considered bought or made otherwise dependent by some means. Traditionally, the goal of the secret service professional is to ensnare any potential-value source of information with a psychological net, and pull tight this net at the appropriate time. There are not too many possibilities for this, but those secret agents who develop controllable sources of information will get promotions and the respect of colleagues. However, the methods and behavioral techniques that are needed to attain this goal . . .

Information given: Tableau, encrypted text, contextual environment clues ‘MEDUSA’ cast on wall, only latin letters

Method commonly cited: Only two solutions cited, neither are entirely comprehensive

Actual method: Quagmire III cipher, running key of [ТЕНЬ] ,key of [ЙБАСГТ]. This was a big frustration for myself as well as workers on the project as ЙБАСГТ is implied to be a misspelling of МЕДУЗА, the Cyrillic equivalent of Medusa.

Explanation:

The projector on the most technical level can be classified as a ‘modified Quagmire III cipher using a compressed cyrillic alphabet’. It works a little bit like this…

① Step One: Adjust the Alphabet (32 → 31 letters)

  • Start with the original Cyrillic alphabet (32 letters).
  • You remove the distinction between the two letters Ш and Щ, treating them as one single letter.
  • This adjustment gives you an alphabet of 31 letters.

Adjusted Alphabet (paired ШЩ):

А Б В Г Д Е Ж З И Й К Л М Н О П Р С Т У Ф Х Ц Ч ШЩ Ъ Ы Ь Э Ю Я

② Step Two: Creating the Cipher Alphabet

  • Take the keyword “ТЕНЬ” (Shadow), and write these letters first.
  • Then write down all the other letters of the adjusted alphabet, without repeating any from the keyword:

Cipher Alphabet after applying “ТЕНЬ“:

Т Е Н Ь А Б В Г Д Ж З И Й К Л М О П Р С У Ф Х Ц Ч ШЩ Ъ Ы Э Ю Я

③ Step Three: Quagmire III Cipher Decoding

  • Now, you decode each letter of your secret encoded message using a standard Quagmire III cipher.

The decoding uses the key: “ЙБАСГТ” (which is the misspelled “MEDUSA” transliteration, intentionally scrambled from the puzzle’s clues).

You apply a single-key Vigenère style cipher over the compressed alphabet and then decode with this keyword (“ЙБАСГТ”), meaning you:

  • Find the position of the encoded letter in the special cipher alphabet.
  • Subtract the position of your keyword letter (“ЙБАСГТ”) from that position.
  • Wrap around using mod 31 if you go below zero.
  • The resulting position is your decoded letter from your adjusted 31-letter alphabet.

TL;DR:

  • Alphabet shrinks from 32 → 31 letters (pairing ШЩ).
  • “ТЕНЬ” creates a rearranged alphabet.
  • “ЙБАСГТ” decodes your secret message letter-by-letter.

Verifiable solution:

[To run, create a python file, then in the cmd, run that python file, these are as simple as possible so that even someone who does not understand code can go through them easily. Or visit this github page.]

# Correct Cyrillic Projector decoding script
# Explicitly handles pairing ШЩ as instructed.

# Normal Cyrillic alphabet provided explicitly (without Ё)
normal_cyrillic_alphabet = 'АБВГДЕЖЗИЙКЛМНОПРСТУФХЦЧШЩЪЫЬЭЮЯ'

# Alt-LU Alphabet from instructions, pairing ШЩ explicitly
alt_lu_abc = 'АБВГДЕЖЗИЙКЛМНОПРСТУФХЦЧШЩЪЫЬЭЮЯ'

# Provided keys explicitly from document
key1 = 'ТЕНЬ'  # "Shadow"
key2 = 'ЙБАСГТ'  # Derived from MEDUSA, as per instructions

# Provided encoded message (first segment as example)
encoded_text = 'ЛТФЕЮТФЯЙЯМПХЦФАЧНЩПВБГЖЧСКЬГГЛЗДЭЙП'

# Generate cipher alphabet from keyword
def make_cipher_abc(abc, key):
    cipher_abc = ''
    for char in key + abc:
        if char not in cipher_abc:
            cipher_abc += char
    return cipher_abc

# Adjust index for pairing Ш and Щ as same letter
def get_paired_index(char, abc):
    if char == 'Щ':
        char = 'Ш'
    return abc.index(char)

# Vigenère decoding function using Alt-LU alphabet and pairing ШЩ
def vigenere_decode(encoded, cipher_abc, keyword, alt_lu_abc):
    decoded = ""
    cipher_len = len(cipher_abc)
    for i, char in enumerate(encoded):
        if char in cipher_abc:
            cipher_idx = get_paired_index(char, cipher_abc)
            key_char = keyword[i % len(keyword)]
            key_idx = get_paired_index(key_char, cipher_abc)
            decoded_idx = (cipher_idx - key_idx + cipher_len) % cipher_len
            decoded_char = alt_lu_abc[decoded_idx]
            decoded += decoded_char
        else:
            decoded += char
    return decoded

# Generate cipher alphabet from key1
cipher_abc = make_cipher_abc(normal_cyrillic_alphabet, key1)
cipher_len = len(cipher_abc)

# Perform decoding with correct Alt-LU
decoded_text = vigenere_decode(encoded_text, cipher_abc, key2, alt_lu_abc)

# Print the correctly decoded message
print("Correctly Decoded message:")
print(decoded_text)