diff --git a/README.md b/README.md
index ad730b4..46f73a5 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,17 @@
 # aes-project
+AES-128, and square attack against reduced AES-128 (only 4-turns) implementation in rust.
 
+### example
+encrypt the text "Hello, world!" using the key 2b7e151628aed2a6abf7158809cf4f3c, hex-encoded. 10-turns AES-128
+
+```
+cargo run -- encrypt -K -k '2b7e151628aed2a6abf7158809cf4f3c' -t "Hello, world!" -n 10
+```
+square attack against 4-turns AES-128, choosen key bba51a66aca801747294ff4317fb59e2, hex-encoded.
+```
+cargo run -- findkey bba51a66aca801747294ff4317fb59e2 -K
+```
+square attack against 4-turns AES-128, 10 keys generated randomly.
+```
+cargo run -- square 10
+```
diff --git a/src/aes.rs b/src/aes.rs
index a114d44..878a591 100644
--- a/src/aes.rs
+++ b/src/aes.rs
@@ -324,7 +324,7 @@ impl Aes {
             original_key[i / 4][i % 4] = key_bytes[i];
         }
 
-        // AES128, 11 rounds, i ∈ [0;4*rounds-1]
+        // AES128, 10 rounds + pre-whitening, i ∈ [0;4*rounds-1]
         for i in 0..44 {
             if i < n {
                 expanded_key[i] = original_key[i];