We have found one software suitable in our database for this conversion.
The only way to produce digitally signed databases in MS Access is to save them as .accdc files with proper certificate. There is really no alternative for this as this format is exclusive to Access. You also will need viable digital certificate.
Access databases can be made based on SQL files, so this is probably the case of sql to accdc conversion as well.
SQL
Files with sql extension are used for SQL (Structured Query Language) data files. These are used to exchange or export/import data from relational SQL databases, contains various SQL instructions etc. It is a text file, but only useful together with various sql database servers and sql management software.
ACCDC
An accdc file extension is related to the Microsoft Access a database management system for Microsoft Windows. An accdc file stores digitally signed database.