Security lattice model of information flow
 

1. Establish a lattice model of information flow

what isInformation Flow ？
Information FlowIs a set of information in the same direction in space and time, it hascommonofInformation SourcewithInformation recipient。
This model is common in military systems and government systems because they areFlow of informationHavestrictoflimit。

• bossOnlyAccept reports from subordinates,Can'tInform subordinates;
• Between different departmentsCan'tCommunicate with each other.
• Government departments as shown in the figure below. rightLine segment with arrowExpressinformationofflow。

• set upInformation lattice model：

model:Different power rangesuseSubset latticeL1，Different levelsuseLinear gridL2. CorrectDescription of permissionsuseLinear gridwithSubset latticeofProduct L2 x L1
(a, b)≤(c,d) a≤c and bD, that isThe same department and low level。
 When only (a, b) ≤ (c, d), the information can be from (a, b)main bodyFlow permissions are (c, d)main body。

Simplify the above information flow model, as follows: (Use a representative meta representation at the same level in the same department)

The information grid model established is as follows:

(The only information flow scenario is the limitation set in the model, that is, only (a, b) ≤ (c, d), the information can be from the authority (a, b)main bodyFlow permissions are (c, d)main body）                                   

Second, transform the original information flow into a lattice model

andreal worldMany streams of informationDoes not constitute a lattice model, But we can still passRemodelMake the original information flowInformation flow model. And the information flow after transformation is consistent with the original flow, and after transformation, we canBetter controlInformation systemFlow of information. For example:

From the comparison of the above figure, we can see that we first merged the BCH, and then added many nodes to make the entire information flow form a grid. For example, new nodes such as E∧F, E∨F, D∨G, and A∨I are added.