Hash Table

Every document saved in accordance with the Local Data Audit Policy is stored in a Transient Secure Audit Location (TSAL) designated and controlled within the organisation.


At the end of the designated Audit Period, the document will be transferred to the Permanent Secure Audit Location(PSAL). At some time prior to that transfer, the hash of the document will be created and stored in the Local Document Table (LDT).


One LDT is created for each TSAL and there will normally be one TSAL per user, or possibly per workstation. (In low volume situations, it might make more sense to allocate one TSAL per workgroup, office, department or whatever)


The LDT holds one record for each document in the TSAL.


That record MUST contain the hash of the document, the time-stamp of the document and the file-name. Optionally, and typically, it may also contain more administratively useful data such as the name of the author, the application in which it was created, a brief description and so on.


At the end of the Audit Period, the LDTs are moved to the PSAL where a Local Master Document Table (LMDT) is created. This stores the hashes, time-stamps and TSAL of all the LDTs created during the Audit Period.


Finally, the hash of the LMDT is created and stored in the Local Hash Table, also in the PSAL. This stores each day's (or other audit period) LMDT hash and its time-stamp. It is also this single hash which is submitted to the Codel Database at the end of each audit period.


In a large and busy organisation, that single hash may represent the peak of a hash hierarchy containing several thousand documents.



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