I have 2 text files used by an application. One is a very large "schema" array (approaching 100,000 lines, JSON format). The other is a .txt.sig file generated somehow from the contents of the schema file, which is used as a check by the application to verify the schema file's composition.
If you modify even one character in the schema file, it is detected as corrupt based on the contents of the signature file.
Is there any way to determine how the .sig file contents are generated from the plain text without some sort of key? I would like to create a new .sig file that matches up with a modified version of the schema file for tinkering purposes.
I can link to the Schema file if there is any possibility based on the info I have. It's too large for Pastebin or else I would include it here.
Thanks in advance for your input.
Contents of cipher text: