Cryptography Challenge

Cryptography, or cryptology is the practice and study of techniques for secure communication. Cryptography relies on using more or less complex encryption algorithms to encode a readable message (plaintext) into a collection of characters (ciphertext) that is hard to decipher (decode).

For this challenge, we are giving you a piece of Python code used to encrypt a message.

Your first task is to reverse-engineer this code to understand how this encryption algorithm works. Then, your challenge consists of writing a new function called decrypt(), that takes two parameters (a ciphertext and a key) and returns the plaintext corresponding to the given ciphertext.

Decryption Table..

Using your new decrypt() function, decrypt the following messages:

# Ciphertext Key Plaintext?
#1
YFwoJeELOvlDVrOlNBDConouLwhdCC_mkIjsYeKsuaGsDbSRJymLJVOaYNQRrgKBSifPOdnCbUleWCbf
4
#2
HNABntvVepMaQSNHyKxQTXZf_HVbQXcqJSXfswOAuRBzpefOdfBeylimeqDHDlFc
7
#3
PqKgakYBpfzveAHVrrUgbzpkaMWUcskukxac_QfsWpFSrTrwiaQRtSsXesGlrBqv
3
#4
HXelrEed_fCxojmVersu_Gtehvee_NSluGnJ
1
#5
PHcRrveeRUmDnfqMFAnBJvvwyzSDrj_tqXhrLRXIegaDLwdInIGCvqelcjzU
5
unlock-access

Solution...

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