  Since buffer overflow has long been a frequently occurring, high-risk
vulnerability, various methods have been developed to support spatial memory
safety and prevent buffer overflow. However, every proposed method, although
effective in part, has its limitations. Due to expensive bound-checking or
large memory in taking for metadata, the software-only support for spatial
memory safety inherently entails runtime overhead. Contrastingly,
hardware-assisted methods are not available without specific hardware
assistants. To mitigate such limitations, Herein we propose L4 Pointer, which
is a 128-bit pointer extended from a normal 64-bit virtual addresses. By using
the extra bits and widespread SIMD operations, L4 Pointer shows less slow-down
and higher performance without hardware extension than existing methods.
