## Description* **Name:** [School](https://2019.peactf.com/problems)* **Points:** 100* **Tag:** Crypto


## Tools* Firefox Version 60.8.0 https://www.mozilla.org/en-US/firefox/60.8.0/releasenotes/* Alphabetical Substitution https://www.dcode.fr/ascii-code* Cryptovenom https://github.com/lockedbyte/cryptovenom
## WriteupDownload the file called enc.txt (4fc5d4517a98bd97fede504d6f5e42bc) through the link where we find a cipher text.
```bashroot@1v4n:~/CTF/peaCTF2019/crypto/School# wget https://shell1.2019.peactf.com/static/6999a90c2dc921d2e0de4720df921549/enc.txtroot@1v4n:~/CTF/peaCTF2019/crypto/School# md5sum enc.txte0aee564db0a8f5f26118817784859ef  enc.txtroot@1v4n:~/CTF/peaCTF2019/crypto/School# file enc.txtenc.txt: UTF-8 Unicode textroot@1v4n:~/CTF/peaCTF2019/crypto/School# cat enc.txtAlphabet: ​WCGPSUHRAQYKFDLZOJNXMVEBTIzswGXU{ljwdhsqmags}```We use the AS online tool to decipher the message >

or with Cryptovenom python tool
```bashroot@1v4n:~/CTF/peaCTF2019/crypto/School# git clone https://github.com/lockedbyte/cryptovenom.gitroot@1v4n:~/CTF/peaCTF2019/crypto/School/cryptovenom# python2 cryptovenom.py
 ▄▄· ▄▄▄   ▄· ▄▌ ▄▄▄·▄▄▄▄▄       ▌ ▐·▄▄▄ . ▐ ▄       • ▌ ▄ ·.▐█ ▌▪▀▄ █·▐█▪██▌▐█ ▄█•██  ▪     ▪█·█▌▀▄.▀·•█▌▐█▪     ·██ ▐███▪██ ▄▄▐▀▀▄ ▐█▌▐█▪ ██▀· ▐█.▪ ▄█▀▄ ▐█▐█•▐▀▀▪▄▐█▐▐▌ ▄█▀▄ ▐█ ▌▐▌▐█·▐███▌▐█•█▌ ▐█▀·.▐█▪·• ▐█▌·▐█▌.▐▌ ███ ▐█▄▄▌██▐█▌▐█▌.▐▌██ ██▌▐█▌·▀▀▀ .▀  ▀  ▀ • .▀    ▀▀▀  ▀█▄▀▪. ▀   ▀▀▀ ▀▀ █▪ ▀█▄▀▪▀▀  █▪▀▀▀...-[MENU]-...    4) Classical Algorithms...[=] Option: 4...-[MENU:Classical]-...   11) Simple Substitution Cipher...[=] Option: 11...-=[OPTIONS]=-...   2) Decrypt...[=] Option: 2[=] [F]ile or [T]ext: T[=] Text: zswGXU{ljwdhsqmags}[=] Output format (Eg.: raw or base64): raw[=] Key: WCGPSUHRAQYKFDLZOJNXMVEBTI[+] Out = PEACTFORANGEJUICE[+] All done!```and also you can use the [pycipher module](https://pypi.org/project/pycipher/)```python>>> from pycipher import SimpleSubstitution>>> ss = SimpleSubstitution('wcgpsuhraqykfdlzojnxmvebti')>>> ss.decipher('zswGXU{ljwdhsqmags}')'PEACTFORANGEJUICE'````
### Flag```bash___   ____   ____      _                                                         __           __                     _     _ ___     ____     ___ _  ,"___"./_  _\ F ___J   ."_J    ____    _ ___   ___ _   _ ___     ___ _    ____     LJ   _    _  LJ   ____     ____    F_".   J '__ J   F __ J   F __` L FJ---L][J  L]J |___: _/ /-'   F __ J  J '__ ",F __` L J '__ J   F __` L  F __ J     _  J |  | L     F ___J.  F __ J   '-\ \_| |--| | | _____J | |--| |J |   LJ |  | | _____|_ (/    | |--| | | |__|-| |--| | | |__| | | |--| | | _____J   J J | |  | | FJ | |---LJ | _____J    \) _|F L__J J F L___--.F L__J J| \___--.F  J F |____L_L."-__ F L__J J F L  `-F L__J J F L  J J F L__J J F L___--.  J  LF L__J JJ  LF L___--.F L___--.__-".J_JJ  _____/J\______/J\____,__J\_____/J____J__F      "_"-__J\______/J__L   J\____,__J__L  J__L)-____  J\______/,-_J  J\____,__J__J\______/J\______/J__-"_"  |_J_____F J______F J____,__FJ_____F|____|__|        "-__|J______F|__L    J____,__|__L  J__J\______/FJ______F\_____/J____,__|__|J______F J______F|__-"    L_J                                                                                        J______F         \_____/                                      ```