Tags: substitution 

Rating: 5.0

Here is the ciphertext:
```$$=-=->;#&+%,_(*#^[|>;$$$^$^!@(*>;..(*$^$$..?(>;[]$$%),_$$[|,_>;(*[|?:>=#&>=,_?((*>;..$$|}$$@%>=>=?(?:>;=$$@%$^>=[|>;[]$^|},_[|?(..,_(*#^?($$#&>=[|>;>;?(:{$$$^$^[|>;#^>=[|,_[|?([]$$[|$^,_[|[|$^>=@%>;+%|}>;[][][|?:>=#^#&>;=@%>=>=>;[]=->;=[]$^,_>=?($$(*|}..$$|}@%>==-$$=@%>=>=?(+%>;(*[|=-$$#&>=..?:$$[|?:;?(?(,_@%$^>=|}>=$^$^>;..@%$^$$=-!@|}>=$^$^>;..@%$^$$=-!@|}>=$^$^>;..@%$^$$=-!@|}>=$^$^>;..@%$^$$=-!@>;>;?:@%$^$$=-!@$$(*+%|}>=$^$^>;..$^>=[|?(?(?:$$!@>=,_[|=@%$$#&#&|}@%#&>=$$!@[]$$?([|,_?(#&>=$$+%|}?:>=#&>=,_?([|?:>=[]$^$$#^?([|,_$^$^?:$$%)>=(*[|?(>=>=(*[|?:>=[];%),_>=@%>=#^,_(*(*,_(*#^[|>;>=(*+%```

This cipher is replacing one letter with two special characters. You can do frequency analysis on this to convince yourself that this must be right (https://www.dcode.fr/frequency-analysis).

Here is a quick script to convert every two special characters into some letter so we can use an online substitution solver online:
```python
import string

ciphertext = "$$=-=->;#&+%,_(*#^[|>;$$$^$^!@(*>;..(*$^$$..?(>;[]$$%),_$$[|,_>;(*[|?:>=#&>=,_?((*>;..$$|}$$@%>=>=?(?:>;=$$@%$^>=[|>;[]$^|},_[|?(..,_(*#^?($$#&>=[|>;>;?(:{$$$^$^[|>;#^>=[|,_[|?([]$$[|$^,_[|[|$^>=@%>;+%|}>;[][][|?:>=#^#&>;=@%>=>=>;[]=->;=[]$^,_>=?($$(*|}..$$|}@%>==-$$=@%>=>=?(+%>;(*[|=-$$#&>=..?:$$[|?:;?(?(,_@%$^>=|}>=$^$^>;..@%$^$$=-!@|}>=$^$^>;..@%$^$$=-!@|}>=$^$^>;..@%$^$$=-!@|}>=$^$^>;..@%$^$$=-!@>;>;?:@%$^$$=-!@$$(*+%|}>=$^$^>;..$^>=[|?(?(?:$$!@>=,_[|=@%$$#&#&|}@%#&>=$$!@[]$$?([|,_?(#&>=$$+%|}?:>=#&>=,_?([|?:>=[]$^$$#^?([|,_$^$^?:$$%)>=(*[|?(>=>=(*[|?:>=[];%),_>=@%>=#^,_(*(*,_(*#^[|>;>=(*+%"

mapping = {}
chars = list(string.ascii_lowercase)
output = ""

for i in range(0, len(ciphertext), 2):
bigram = ciphertext[i:i+2]
if bigram not in mapping:
mapping[bigram] = chars.pop()
output += mapping[bigram]

print(output)
```

Output:
```console
zyyxwvutsrxzqqptxotqzonxmzluzruxtrkjwjuntxozizhjjnkxgqvhjzhqjrxmqiurnoutsnzwjrxxnfzqqrxsjrurnmzrqurrqjhxvixmmrkjswxgtvrkjhjjxmyxgwnjmqujnztiozihjyzgnjhjjnvxtryzwjokzrkgfztnrkutpunufexnnuhqjijqqxohqzypijqqxohqzypijqqxohqzypijqqxohqzypxxkhqzypztvijqqxoqjrnnkzpjurgezqurrqjhzwwihwjzpmznrunwjzvikjwjunrkjmqzsnruqqkzljtrnjjtrkjmgqqfxlujhjsuttutsrxjtv
```

Now plug it in https://www.boxentriq.com/code-breaking/cryptogram to solve it:

Original writeup (https://github.com/NihilistPenguin/PatriotCTF2022-Writeups/blob/main/Crypto/Barry.md).