diff --git a/chals/crypto/diagonal/Dockerfile b/chals/crypto/diagonal/Dockerfile
new file mode 100644
index 0000000..4e00805
--- /dev/null
+++ b/chals/crypto/diagonal/Dockerfile
@@ -0,0 +1,14 @@
+FROM ubuntu:20.04
+
+RUN apt-get update && apt-get install -y socat python3
+
+RUN adduser chal
+
+RUN mkdir -p /chal
+WORKDIR /chal
+
+COPY chal.py flag.txt ./
+RUN chmod 555 chal.py
+USER chal
+
+CMD socat -T60 TCP-LISTEN:1337,fork,reuseaddr EXEC:"python3 -u chal.py",stderr
diff --git a/chals/crypto/diagonal/challenge.yml b/chals/crypto/diagonal/challenge.yml
new file mode 100644
index 0000000..6b65c76
--- /dev/null
+++ b/chals/crypto/diagonal/challenge.yml
@@ -0,0 +1,25 @@
+name: "Diagonal"
+author: Anakin
+category: Crypto
+description: |-
+  We've tried and failed with horizontal and vertical integration.
+  Hopefully something more angular will catch on.
+
+  `nc chal.fallctf.sigpwny.com 6001`
+
+  **author**: Pete
+value: 500
+type: dynamic
+tags:
+  - medium
+extra:
+  initial: 500
+  decay: 150
+  minimum: 100
+flags:
+  - sigpwny{mult1d1m3n510n4l}
+files:
+  - public.py
+hints:
+  - Play with some matrices, see how the exponent affects the entries, get some equations going
+state: hidden
diff --git a/chals/crypto/diagonal/chal.py b/chals/crypto/diagonal/public.py
similarity index 53%
rename from chals/crypto/diagonal/chal.py
rename to chals/crypto/diagonal/public.py
index 3ef05fd..da82c4a 100644
--- a/chals/crypto/diagonal/chal.py
+++ b/chals/crypto/diagonal/public.py
@@ -1,12 +1,10 @@
 import numpy as np
 import random
 
-import sympy as sp
-
-FLAG = "sigpwny{testing_yay!}"
+FLAG = "sigpwny{????????????????}"
 
 def inputs():
-    print("Define a 3 x 3 Integer Matrix M")
+    print("[D] Define a 3 x 3 Integer Matrix M")
     M = [
         [0, 0, 0],
         [0, 0, 0],
@@ -14,40 +12,44 @@ def inputs():
     ]
     for i in range(3):
         for j in range(3):
-            M[i][j] = int(input(f"[D] M[{i}][{j}] = "))
+            try:
+                M[i][j] = int(input(f"[D] M[{i}][{j}] = "))
+            except:
+                return None
     return M
 
 def fun(M_, d):
-    M = np.matrix(M_)
+    M = np.matrix(M_, dtype='object')
     M = M**d
 
+    # [\\\]
+    # [ \\]
+    # [  \]
     return M[0, 0] + M[1, 1] + M[2, 2] + M[0, 1] + M[1, 2] + M[0, 2]
 
 def main():
     secret = random.randint(1_000_000_000, 10_000_000_000)
 
+    print("[D] Welcome")
     M = inputs()
+    if M == None:
+        print("[D] You tried something weird...")
+        return
+
     res = fun(M, secret)
     print()
     print(f"[D] Have fun: {res}")
     print()
-    guess = int(input(f"[D] Make a guess: "))
+    try:
+        guess = int(input(f"[D] Make a guess: "))
+    except:
+        print("[D] You tried something weird...")
+        return
 
     if guess == secret:
         print(f"[D] {FLAG}")
     else:
         print(f"[D] Better luck next time!")
 
-
-    # # Some test solutions
-    # disc = (25 - 4 * (6 - 2*int(res)))**(0.5)
-    # sec_ = (-5 + disc) // 2
-    # print(sec_)
-
-    # n = sp.Symbol('n')
-    # print(sp.solve(3 + 2*n + (n**2 + n) / 2 - res, n))
-
-
-
 if __name__ == "__main__":
     main()
diff --git a/chals/crypto/diagonal/server.py b/chals/crypto/diagonal/server.py
new file mode 100644
index 0000000..7956eb9
--- /dev/null
+++ b/chals/crypto/diagonal/server.py
@@ -0,0 +1,55 @@
+import numpy as np
+import random
+
+FLAG = "sigpwny{mult1d1m3n510n4l}"
+
+def inputs():
+    print("[D] Define a 3 x 3 Integer Matrix M")
+    M = [
+        [0, 0, 0],
+        [0, 0, 0],
+        [0, 0, 0],
+    ]
+    for i in range(3):
+        for j in range(3):
+            try:
+                M[i][j] = int(input(f"[D] M[{i}][{j}] = "))
+            except:
+                return None
+    return M
+
+def fun(M_, d):
+    M = np.matrix(M_, dtype='object')
+    M = M**d
+
+    # [\\\]
+    # [ \\]
+    # [  \]
+    return M[0, 0] + M[1, 1] + M[2, 2] + M[0, 1] + M[1, 2] + M[0, 2]
+
+def main():
+    secret = random.randint(1_000_000_000, 10_000_000_000)
+
+    print("[D] Welcome")
+    M = inputs()
+    if M == None:
+        print("[D] You tried something weird...")
+        return
+
+    res = fun(M, secret)
+    print()
+    print(f"[D] Have fun: {res}")
+    print()
+    try:
+        guess = int(input(f"[D] Make a guess: "))
+    except:
+        print("[D] You tried something weird...")
+        return
+
+    if guess == secret:
+        print(f"[D] {FLAG}")
+    else:
+        print(f"[D] Better luck next time!")
+
+if __name__ == "__main__":
+    main()
diff --git a/chals/crypto/diagonal/sol.py b/chals/crypto/diagonal/sol.py
new file mode 100644
index 0000000..9060e31
--- /dev/null
+++ b/chals/crypto/diagonal/sol.py
@@ -0,0 +1,18 @@
+import sympy as sp
+
+def main():
+
+    res = 18669237451167230340
+
+    # Some solutions
+    disc = (25 - 4 * (6 - 2*int(res)))**(0.5)
+    sec_ = (-5 + disc) // 2
+    print(int(sec_))
+
+    n = sp.Symbol('n')
+    print(sp.solve(3 + 2*n + (n**2 + n) / 2 - res, n)[1])
+
+
+
+if __name__ == "__main__":
+    main()