The necessary access control implementation which uses LSM in the kernel, mainly based on the principle of less-known preferences. Well, it is not a Linux distribution but you can call it as a combination set of modification which can be applied to Unix-O.S.
This was initially developed by the US National Security Agency and was released in 2000; other development teams include Network Associates, Secure Computing Corporation, and Tresys.
It is basically a FLASK implementation which is integrated in the versions of the Linux kernel with different utilities which are designed to demonstrate the value of necessary access controls. A kernel like this consists of architectural components which are prototyped in the Fluke O.S. The kernel integrating SELinux pressurizing necessary access control policies which confine user programs and system servers to the minimum amount of preference.
This reduces ability of the programs to harm. The mechanism works on its own compared to the traditional Linux access control mechanisms. There is no concept like the “root” super user and does not share like the old Linux security mechanisms. This security depends upon the correction of the kernel, preference application and every configuration. Any problems in this segment, can lead to serious damage to the entire system whereas the security of a modified system is based on the security-enhanced Linux kernel.