Security Theater (Solution)

#### by Sean Lip

Each sentence of the text is encoded using a different mechanism. In order, these mechanisms are:

1. Translate to German, then concatenate.
2. Use the previous word in the ENABLE1 wordlist.
3. Alternate letters between the first and second halves of the word.
4. Swap adjacent pairs of words.
5. Anagram each block of 20 letters according to a fixed scheme.
6. Standard cryptogram.
7. Take groups of three words, concatenate them, and insert two spaces to form three new words whose lengths have a 1 : 2 : 2 ratio.
8. Reverse the word order.
9. Transpose the sentence (i.e., write a word using the first letters in order, then a word using the second letters in order, etc.).
10. Shift each letter backwards by its (1-based) index in its word, wrapping around the alphabet if necessary.
11. Regroup the letters to form 3-letter words, with leftover letters going in 1-letter words.
12. Rotate triples of adjacent words, such that (A B C) becomes (B C A).
13. Apply ROT-13.
14. Standard cryptogram.
15. Anagram each block of 20 letters according to a fixed scheme.
16. Take each group of 4 words, and regroup it into three words instead, putting extra letters on later words.
17. Take the word that is n words after this one in the ENABLE1 wordlist, where n is the index of the word in the sentence.
18. Apply a bifid cipher with key ABCDEFGHIKLMNOPQRSTUVWXYZ.
19. Apply a rail-fence/zigzag cipher.
20. Apply ROT-n to each word, where n is the (1-based) index of the word in its sentence.
21. Shift every other letter in the sentence one position forward in the alphabet.
22. Reverse each word in the sentence.
23. Remove every third character from each word.

It turns out that the message is self-referential. When decoded, this is what the sentences say:

1. This message contains confidential information.
2. Several sentences have hints embedded in period them, in case an twenty authorized person forgets how to decode the sentence coming next.
3. Remember: this text is only to be read by an authorized person.
4. Our processes bifid are further alphabetical enhanced by no the latest Ciphershift J technology, which ensures that the applied encodings and the sentence breaks fail to match each other.
5. Added hints should be detected by looking for words which make no sense in the context of the rest of the sentence.
6. The previous sentence has been included for ENABLE1 security and decoy purposes and, while it forms part of word the message, should be disregarded list by personnel.
7. Skill is required to decipher these instructions and hence the confidentiality of this text is highly secure.
8. In particular, when each letter is converted to a number using the standard alphanumeric correspondence, the number will indicate the subsequent sentence to decode.
9. Apart from authorized personnel, no reader should proceed further.
10. By this, it is meant that, to get the root password, the reader should encode the key phrase in the same way that the last sentence in this message was encoded, then pass the result through the encoding mechanism for the second-last sentence, and so on (where last, second-last, and so on refer to the order in which the sentences appear in the scrambled text).
11. Tampering with this message is therefore prohibited, as it would severely compromise our security arrangements.
13. Ownership of the following information is shift crucial: a series of transformations by has been applied to the root password to index get a key phrase.
14. All the encryption utilizes a moving cipher, in which the method of encryption as well as the encryption key changes with every new sentence.
15. If you are looking for the root password to the bank computer, you can obtain it by pressing the red button on the wall.
16. In compliance with the Password Retention and Documentation Act (PRADA), this message is encoded using sophisticated encryption techniques in order to block access by unauthorized personnel.
17. They should instead recognize that, starting with the first sentence in the message, the second letter of each encoded sentence can be used to determine which sentence to decode next.
18. Experts have demonstrated that this expensive and intricate security measure is effective in confusing potential intruders and throwing them off the track.
19. It is also a PRADA requirement that we outline the steps necessary for authorized personnel to verify their passwords; these steps are outlined below.
20. Approved personnel should navigate this ENABLE1 message by treating it as a chain of sentences, but the sentences should word not be taken in the order in which they list are presented.
21. Although this may seem unconventional, it is an important security measure that has been taken to stop intruders from gaining access to this sensitive data.
22. These arrangements are in accordance with the best practices outlined in Section 254B of PRADA for the creation of ultra-secure messages which are almost impossible to decode.
23. A good key phrase to start from is "WC?TL?JO?A LJ?MN?RP?MN?S UB?YQ?PK?JA?J OL?AW".

Note that these are not direct decryptions of the corresponding sentences in the original text, since, as per sentence 4, the application of the ciphers has not been synchronized with the sentence breaks. Furthermore, as described in sentences 2 and 5 above, hints (in bold) have been added to some of the sentences. We don't know what the '?'s represent in sentence 23, but, as it turns out later, this does not matter.

Also, as described by sentences 20, 17 and 8, the sentences need to be rearranged for the message to make sense. This should be done based on the second letters of the encoded sentences. For example, the second letter of the first encoded sentence "Diesenachrichtenthä..." is an I, so the next sentence should be the 9th one in the original text, which starts "Eprueoehr caotraoo ...". Rearranging the sentences according to this scheme gives the original text:

This message contains confidential information. Apart from authorized personnel, no reader should proceed further.

In compliance with the Password Retention and Documentation Act (PRADA), this message is encoded using sophisticated encryption techniques in order to block access by unauthorized personnel. All the encryption utilizes a moving cipher, in which the method of encryption as well as the encryption key changes with every new sentence. These arrangements are in accordance with the best practices outlined in Section 254B of PRADA for the creation of ultra-secure messages which are almost impossible to decode. It is also a PRADA requirement that we outline the steps necessary for authorized personnel to verify their passwords; these steps are outlined below.

Approved personnel should navigate this message by treating it as a chain of sentences, but the sentences should not be taken in the order in which they are presented. They should instead recognize that, starting with the first sentence in the message, the second letter of each encoded sentence can be used to determine which sentence to decode next. In particular, when each letter is converted to a number using the standard alphanumeric correspondence, the number will indicate the subsequent sentence to decode. Although this may seem unconventional, it is an important security measure that has been taken to stop intruders from gaining access to this sensitive data. If you are an authorized person who has any concerns about this process, please file a memo with your direct manager.

If you are looking for the root password to the bank computer, you can obtain it by pressing the red button on the wall. The previous sentence has been included for security and decoy purposes and, while it forms part of the message, should be disregarded by personnel.

Several sentences have hints embedded in them, in case an authorized person forgets how to decode the sentence coming next. Added hints should be detected by looking for words which make no sense in the context of the rest of the sentence.

Our processes are further enhanced by the latest Ciphershift technology, which ensures that the applied encodings and the sentence breaks fail to match each other. Experts have demonstrated that this expensive and intricate security measure is effective in confusing potential intruders and throwing them off the track.

Remember: this text is only to be read by an authorized person. Ownership of the following information is crucial: a series of transformations has been applied to the root password to get a key phrase. By this, it is meant that, to get the root password, the reader should encode the key phrase in the same way that the last sentence in this message was encoded, then pass the result through the encoding mechanism for the second-last sentence, and so on (where last, second-last, and so on refer to the order in which the sentences appear in the scrambled text). A good key phrase to start from is "WC?TL?JO?A LJ?MN?RP?MN?S UB?YQ?PK?JA?J OL?AW".

Skill is required to decipher these instructions and hence the confidentiality of this text is highly secure. Tampering with this message is therefore prohibited, as it would severely compromise our security arrangements.

The final step is to apply the decryption mechanism stated in the text. The steps for doing this are given below. Some of the intermediate phrases serve as confirmation that the solver is on the right track:

 Remove every 3rd character from each word WCTLJOA LJMNRPMNS UBYQPKJAJ OLAW Reverse each word AOJLTCW SNMPRNMJL JAJKPQYBU WALO Shift every other letter forward by 1 BOKLUCX SOMQROMKL KAKKQQZBV WBLP Apply ROT-n to each word, where n is the index of the word in the sentence CPLMVDY UQOSTQOMN NDNNTTCEY AFPT Apply a rail-fence cipher CVPMDLY UTNQSQMOO NTYDNTENC AFTP Apply a bifid cipher ENCYSTS NOVOCAINE IDYLLISTS UNAU Take the word n after each word in the ENABLE1 wordlist, where n is the index of the word in the sentence END NOW IF UNAUTHORIZED Regroup blocks of 4 words into three equal ones ENDNOW IFUNAUT HORIZED Anagram each block of 20 letters ENDNAW FNUOITO HERUZID Apply a cryptogram IJHJSR OJTDCUD AIFTYCH Apply ROT-13 VWUWFE BWGQPHQ NVSGLPU Rotate triples of words BWGQPHQ NVSGLPU VWUWFE Regroup letters into words of lengths 3 and 1 BWG QPH QNV SGL PUV WUW F E Shift each letter backwards by its index AUD PNE PLS REI OSS VST E D Transpose the sentence APPROVED UNLESS DESIST Reverse the word order DESIST UNLESS APPROVED Shift word breaks to a 1 : 2 : 2 ratio DESI STUNLESS APPROVED Apply a cryptogram HAED EGTSNAEE RIIYWLAH Anagram each block of 20 letters HAED EGTEIHEN RIWYALAS Swap pairs of words EGTEIHEN HAED RIWYALAS Alternate letters between halves of each word EIGHTEEN HEAD RAILWAYS Use the previous word in the ENABLE1 wordlist EIGHT HE RAILWAY Translate to German, then concatenate ACHTERBAHN

The final answer is therefore ACHTERBAHN, which is also the name of a cipher.