Query processing and access control in a blockchain network

An apparatus, comprising:

• a processor configured to:
• identify a query from a requesting entity, wherein the query requests access to one or more blockchains;
• convert the query to an expression tree;
• create one or more expression tree variations based on the expression tree, wherein the one or more expression tree variations provide one or more different expressions than the expression tree and a same result as the expression tree;
• determine access conformity between the one or more expression tree variations and the expression tree;
• select an expression tree variation with a greatest conformity rating;
• perform the query using the expression tree variation with the greatest conformity rating;
• and
• provide query results to the requesting entity.

A non-transitory computer readable storage medium configured to store instructions that when executed cause a processor to perform:

• identifying a query from a requesting entity, wherein the query requests access to one or more blockchains;
• converting the query to an expression tree;
• creating one or more expression tree variations based on the expression tree, wherein the one or more expression tree variations provide one or more different expressions than the expression tree and a same result as the expression tree;
• determining access conformity between the one or more expression tree variations and the expression tree;
• selecting an expression tree variation with a greatest conformity rating;
• performing the query using the expression tree variation with the greatest conformity rating;
• and
• providing query results to the requesting entity.