Protecting data is disclosed, including: analyzing, using one or more processors, a set of scripting resource source data to determine a plurality of semantic units; determining a tree-structured source data based at least in part on mapping values of the plurality of semantic units to respective ones of a plurality of semantic structures; selecting an obfuscation strategy to apply to the tree-structured source data, wherein the selected obfuscation strategy includes one or more obfuscation techniques; determining an obfuscated tree-structured source data based at least in part by applying the selected obfuscation strategy to the tree-structured source data; and converting the obfuscated tree-structured source data into a set of obfuscated scripting resource source data.