diff --git a/08-cipher/lib/substitution.coffee b/08-cipher/lib/substitution.coffee
index 66867e1..b4d9a6e 100644
--- a/08-cipher/lib/substitution.coffee
+++ b/08-cipher/lib/substitution.coffee
@@ -4,11 +4,23 @@ alphabet1 = 'abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ'
 
 
 exports.encrypt = (string) ->
-  #
-  # !!! Place your solition here !!!
-  #
-  return 'fix me'
+const crypto = require('crypto');
 
+const algorithm = 'aes-256-ctr';
+const secretKey = 'vOVH6sdmpNWjRRIqCc7rdxs01lwHzfr3';
+const iv = crypto.randomBytes(16);
+
+const encrypt = (text) => {
+
+    const cipher = crypto.createCipheriv(algorithm, secretKey, iv);
+
+    const encrypted = Buffer.concat([cipher.update(text), cipher.final()]);
+
+    return {
+        iv: iv.toString('hex'),
+        content: encrypted.toString('hex')
+    };
+};
 
 exports.decrypt = (string) ->
   result = ''