From 0a4f528785f8860465819540176c0fe66558ee60 Mon Sep 17 00:00:00 2001 From: Aadit Agrawal Date: Wed, 30 Oct 2024 23:29:06 +0530 Subject: [PATCH] Add Technical/picoCTF/t1/q2.md --- Technical/picoCTF/t1/q2.md | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 Technical/picoCTF/t1/q2.md diff --git a/Technical/picoCTF/t1/q2.md b/Technical/picoCTF/t1/q2.md new file mode 100644 index 0000000..2fdcfbd --- /dev/null +++ b/Technical/picoCTF/t1/q2.md @@ -0,0 +1,33 @@ +Question: Easy1 +Key: picoCTF{CRYPTOISFUN} + +Core concept: Vignere Cypher - Decrypted character=(Encrypted character−Key character+26)mod26 + +Can be solved by an easy Python script: + +```py +def decrypt_vigenere(encrypted_text, key): + decrypted_text = "" + key_length = len(key) + + for i in range(len(encrypted_text)): + encrypted_char_pos = ord(encrypted_text[i]) - ord('A') + key_char_pos = ord(key[i % key_length]) - ord('A') + + decrypted_char_pos = (encrypted_char_pos - key_char_pos + 26) % 26 + + decrypted_char = chr(decrypted_char_pos + ord('A')) + + decrypted_text += decrypted_char + + return decrypted_text + + +encrypted_flag = "UFJKXQZQUNB" +key = "SOLVECRYPTO" + +decrypted_flag = decrypt_vigenere(encrypted_flag, key) +print("Decrypted Flag:", decrypted_flag) +``` + +Output: CRYPTOISFUN