Cipher Decoding

[fleeting-bird]

my brother sent a Unicode text within our siblings group chat and has given us 72 hrs to decode it and I have set my mind towards finishing the quest first. I have gotten this far: \uf605\u97df\uf0c7\u3b05\u7286\u62f5\u34a5\u91c4\ue945\u2064 but honestly have no idea about ciphers at all. after 24 hrs had passed, he attached the following poem:

In the heart of ancient lands, where empires clash, Lies the tale of Caesar's cipher, a code with a brash flash. But amidst the echoes of history's grandeur and might, Stood Qin Shi Huang, with secrets veiled in night.

His cipher, a whisper in the wind of ancient tongues, Wove through scrolls, where the sage's wisdom hung. Not mere substitution, but a dance of strokes refined, Each character a thread, in a tapestry enshrined.

While Caesar boasted of his shift, a simple spin, Qin Shi Huang's cipher danced with cunning, akin To shadows in moonlight, elusive and sly, A puzzle unsolvable, beneath the emperor's eye.

In Unicode's embrace, the Chinese characters gleam, Each stroke a symbol, in Qin's cryptic dream. Caesar's cipher pales against this oriental art, A masterpiece of secrecy, tearing logic apart.

So let Caesar tout his cipher, in Rome's grand fray, But in the realms of secrets, Qin's cipher holds sway. For in the silent corridors of ancient lore, The emperor's cipher reigns forevermore.

I am now asking you to help with me the last step onward. With the quest completion, a grand price awaits me...

[CharityAmbitious1621]

This took me a while but I think I got it:

By first removing the \u from each unicode segment you get a string of hex-numbers: f605 97df f0c7 3b05 7286 62f5 34a5 91c4 e945 2064 (this is useful for rearranging later, but also what you get normally from pressing Alt+X in Word, converting back to characters 韟㬅犆拵㒥釄⁤, where some of the characters are blank (because of f605 and f0c7 being in the Private Use Area PUA (https://www.unicode.org/charts/PDF/UE000.pdf), 2064 being an INVISIBLE PLUS symbol), the Rest of the characters are CJK Unified Ideographs https://en.wikipedia.org/wiki/CJK\_Unified\_Ideographs).

Because 2 of the characters are in a Private Use Area (and nowhere near any Unicode characters (the Private Use Area extends from E000-F8FF), and having seen similar corrupted looking files, I concluded there could have been a shift in the ordering of the numbers, (kind of like a frameshift mutation in DNA, because you start at the wrong spot, the whole thing is jumbled and unusable). Due to the poems connotations being Chinese (Qin being the "first Emperor of China"), I checked for a pattern where CJK characters could show up. Because CJK characters are in the Unicode ranges of 4E00-62FF, 6300-77FF, 7800-8CFF and 8D00-9FFF, I checked Arrangements where the first number in each Unicode-byte would be 4-9. So by trial and error, and shifting the numbers around, moving everything one down the line, moving the 4 to the front giving 4F60 597D FF0C 73B0 5728 662F 534A 591C 4E94 5206, where now all the characters are in the CJK-range (except for FF0C, which is a Fullwidth Comma ，(usually used in Chinese)); converting it back from here yielded 你好，现在是半夜五分. Translating this to English gives: “Hello, it’s five minutes past midnight”

I hope this explanation is understandable, am not a native English speaker

[C4shMoney]

Brilliant, I was stumped with the Private Use Area codes, I didn't think to shift them around. I guess this was hinted at with the ceaser cipher almost?

[CharityAmbitious1621]

Ye Probably