diff --git a/src/cipher_analytical_machine/analyzers/simple_substitution.clj b/src/cipher_analytical_machine/analyzers/simple_substitution.clj
index 2c03881..3742489 100644
--- a/src/cipher_analytical_machine/analyzers/simple_substitution.clj
+++ b/src/cipher_analytical_machine/analyzers/simple_substitution.clj
@@ -23,6 +23,13 @@
         (map second)
         (into [])))
 
+(defn get-all-permutation-for-block
+  "Return a vector for all possible blocks that can be made from a vector of symbols."
+  [symbols]
+  (->> (comb/permutations symbols)
+       (map cs/join)
+       (into [])))
+
 (defn get-possible-keys
   "Return possible keys for a possible key vector. For example, if you have a map: {\\a [\\a \\b \\c] \\b [\\b \\c] \\c [\\a \\c]}, then the vector is [[\\a \\b \\c] [\\b \\c] [\\a \\c]] and keys (\"aba\" \"abc\" ...)."
   [possible-key-vector]
diff --git a/test/cipher_analytical_machine/analyzers/simple_substitution_test.clj b/test/cipher_analytical_machine/analyzers/simple_substitution_test.clj
index 5b77935..9ae5566 100644
--- a/test/cipher_analytical_machine/analyzers/simple_substitution_test.clj
+++ b/test/cipher_analytical_machine/analyzers/simple_substitution_test.clj
@@ -14,12 +14,19 @@
       {\a [\a \b] \c [\b \a] \b [\a \c]} "abc" [[\a \b] [\a \c] [\b \a]])))
 
 (deftest get-possible-key-vector-from-reversed-count-map-test
-  (testing ""
+  (testing "The block order must be in descending order"
     (are [reversed-count-map expected-key-vector]
         (= expected-key-vector (get-possible-key-vector-from-reversed-count-map reversed-count-map))
       {1 [\a \c] 2 [\b]}     [[\b] [\a \c]]
       {2 [\a] 1 [\b] 3 [\c]} [[\c] [\a] [\b]])))
 
+(deftest get-all-permutation-for-block-test
+  (testing "It must return all permutations"
+    (are [symbols expected-permutations]
+        (= expected-permutations (get-all-permutation-for-block symbols))
+      [\a \b]    ["ab" "ba"]
+      [\a \b \c] ["abc" "acb" "bac" "bca" "cab" "cba"])))
+
 (deftest get-possible-keys-test
   (testing "The keys must be the all combinations"
     (are [possible-keys-vector expected-keys]