Methods and systems for encoding and protecting data using digital signature and watermarking techniques

A system for detecting modifications to an electronic file, the system comprising:

• a processor;
• and
• a non-transitory computer-readable medium storing instructions that when executed by the processor, cause the system to:
• search the electronic file for the presence of a signature-containing watermark;
• if the signature-containing watermark is found:
• retrieve a signature from the signature-containing watermark, and
• use the signature to verify the authenticity of at least a portion of the electronic file;
• if the signature-containing watermark is not found:
• search the electronic file for a second watermark;
• if the second watermark is found, determine that that the electronic file has been modified;
• if the second watermark is not found, grant a request to use the electronic file.

A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause a computer system to perform a method for detecting modifications to an electronic file, the method comprising:

• searching the electronic file for the presence of a signature-containing watermark;
• if the signature-containing watermark is found:
• retrieving a signature from the signature-containing watermark, and
• using the signature to verify the authenticity of at least a portion of the electronic file;
• if the signature-containing watermark is not found:
• searching the electronic file for a second watermark;
• if the second watermark is found, determining that that the electronic file has been modified;
• if the second watermark is not found, granting a request to use the electronic file.