diff --git a/graphs/graphs.ms b/graphs/graphs.ms
index 2fbcd98..a747f52 100644
--- a/graphs/graphs.ms
+++ b/graphs/graphs.ms
@@ -888,11 +888,14 @@ However, a few security mechanisms exist to prevent data leak or data modificati
 .B "Preventing data leak" .
 Since DODB is a library, any attack on the application using it can lead to a data leak.
 For the moment, any part of the application can access data stored in memory.
-Operating systems provide system calls to protect parts of the allocated memory:
+Operating systems provide system calls to protect parts of the allocated memory.
+For instance,
 .FUNCTION_CALL mlock
-prevents a region of memory from being put in the swap,
+prevents a region of memory from being put in the swap, which may lead to a data leak.
+Also,
 .FUNCTION_CALL mprotect
-prevents the application itself to access part of its own memory unless
+prevents the application itself to access part of its own memory;
+the idea is to read (or write) memory only once you ask for it via a syscall, so you cannot access it from anywhere by mistake (or after an attack).
 .TBD
 
 .B "Discussion on security, not related to DODB" .