Merge pull request #95 from rfritsche/mceliece

Mceliece

1 files changed, 5 insertions, 9 deletions

diff --git a/buch/papers/mceliece/example_code/mceliece_simple.py b/buch/papers/mceliece/example_code/mceliece_simple.py
index bac3b42..c8d5e9d 100644
--- a/buch/papers/mceliece/example_code/mceliece_simple.py
+++ b/buch/papers/mceliece/example_code/mceliece_simple.py
@@ -187,14 +187,10 @@ def decode_linear_code(c, g, syndrome_table):
     q, r=divmod(Poly(c), g)
     q=np.r_[q.coef%2, np.zeros(len(c)-len(q)-len(g)+1)]
     r=np.r_[r.coef%2, np.zeros(len(g)-len(r))]
-    syndrome_index=np.sum([int(a*2**i) for i, a in enumerate(r)])
-    while syndrome_index > 0:
-        c=c ^ syndrome_table[syndrome_index]
-        q, r=divmod(Poly(c), g)
-        q=np.r_[q.coef%2, np.zeros(len(c)-len(q)-len(g)+1)]
-        r=np.r_[r.coef%2, np.zeros(len(g)-len(r))]
-        syndrome_index=np.sum([int(a*2**i) for i, a in enumerate(r)])
-    return np.array(q, dtype=int)
+    syndrome_index=np.sum([int(a*2**i) for i, a in enumerate(r)]) #binary to decimal
+    q_corr, r_corr=divmod(Poly(syndrome_table[syndrome_index]), g)
+    q_corr=np.r_[q_corr.coef%2, np.zeros(len(c)-len(q_corr)-len(g)+1)]
+    return q.astype(int) ^ q_corr.astype(int)
     
 def encode_linear_code(d, G):
     '''
@@ -324,4 +320,4 @@ if __name__ == '__main__':
     
     print(f'msg_rx: {msg_rx}')
         
-        
\ No newline at end of file
+