Validate File Integrity
In this page you can verify the integrity of a PDF copy of a document signed with Proposeful.
Upload the PDF file to check if it originated from Proposeful
File Hash
This is the hash of the file you've provided.Validation
File Hash
This is the hash of the file you've provided.Validation
How can I verify the authenticity of a copy of a document signed with Proposeful?
When signing a document on Proposeful, the system generates a PDF file containing the original document and all data collected from signataries. In this page, you can verify if a PDF file matches a hash that has been generated by our system.
What is a file hash?
A hash is a series of characters generated from a stream of data, in this case the binary content of the PDF file. Every time the file goes through the hashing algorithm, it will output the same hash. Any changes to the PDF file will generate a different hash, which allows you to verify if a PDF file has been altered or if it is exactly like the file generated by Proposeful when signing your document.
How does the hashing algorithm used by Proposeful work?
We use the MD5 hashing algorithm, which allows us to digest any string (in this case, the binary content of the PDF file) and output a 32-character alphanumeric string. The MD5 algorithm is a collision proof, which means no two different files can generate the same MD5 hash.
Can I validate a hash manually?
Yes, first you must convert the PDF file to a base64 string. Now, feed this string (without the data:application/pdf;base64, header) to the MD5 algorithm. The resulting hash must match the hash sent by email when signing the document and the one generated by the validator in this page.
Can Proposeful provide information about a signed document?
No. As stated in our Terms of Service, Proposeful has no knowledge of the content of documents signed on our platform and does not guarantee keeping copies of signed documents. The signataries are responsible for keeping copies of signed documents.