Mini RSA

mini_rsa/sol.py

@@ -0,0 +1,31 @@
+#!/home/maxime/.pyvenv/bin/python3
+from math import sqrt
+
+def iroot(k, n):
+    u, s = n, n+1
+    while u < s:
+        s = u
+        t = (k-1) * s + n // pow(s, k-1)
+        u = t // k
+    return s
+
+with open("ciphertext", 'r') as f:
+    file = f.read().splitlines()
+    N = int(file[0][2:].strip())
+    e = int(file[1][2:].strip())
+    c = int(file[3][16:].strip())
+
+    sol = 3533
+    '''
+    for i in range(10000):
+        c_nomod = c+i*N
+        p = iroot(e, c_nomod)
+        if p**3 == c_nomod:
+            print(i)
+            break
+    '''
+    p = iroot(e, c+sol*N)
+
+    result = p.to_bytes((p.bit_length()+7)//8, byteorder='big')
+    print(result)
+