diff --git a/CHTBCTF/PhaseStream1.py b/CHTBCTF/PhaseStream1.py
new file mode 100644
index 0000000..7ba47e0
--- /dev/null
+++ b/CHTBCTF/PhaseStream1.py
@@ -0,0 +1,17 @@
+from Crypto.Util.number import *;
+
+def xor(bstr1,bstr2):
+    ans = ""
+    for i,j in zip(bstr1,bstr2):
+        ans += chr(i^j)
+    return ans
+
+
+ct = "2e313f2702184c5a0b1e321205550e03261b094d5c171f56011904"
+ct = int(ct,16)
+ct = long_to_bytes(ct)
+key = chr(ct[0]^ord('C')) + chr(ct[1]^ord('H')) + chr(ct[2]^ord('T'))+chr(ct[3]^ord('B'))+chr(ct[4]^ord('{'))
+pt = ""
+for i in range(len(ct)):
+    pt += chr(ct[i] ^ ord(key[i%5]))
+print(pt)