Update cipher.h
diff --git a/include/mbedtls/cipher.h b/include/mbedtls/cipher.h
index 000d18f..2167715 100644
--- a/include/mbedtls/cipher.h
+++ b/include/mbedtls/cipher.h
@@ -1,7 +1,7 @@
 /**
  * \file cipher.h
  *
- * \brief Thif file contains the generic cipher wrapper.
+ * \brief This file contains the generic cipher wrapper.
  *
  * \author Adriaan de Jong <dejong@fox-it.com>
  */