Abstract: A method to validate delivery of a document using a non-repudiation protocol and a time-based one time password (TOTP) for encryption is described. The method includes a one-time registration of an application with a trusted third party, wherein the trusted third party provides a seed to a first device of a first user. The first user receives and accepts a document from a second user. The first device generates the TOTP based on the seed. Using the TOTP as an encryption key, the first device computes a current hash. The delivery of the document can be validated by a second device of a second user based on a comparison of the current clock time and GPS coordinates (optional) of first device as compared to the associated values of the second device. The second device stores the document, first device's computed hash, and current clock time.

Abstract: A method to validate delivery of a document using a non-repudiation protocol and a time-based one time password (TOTP) for encryption is described. The method includes a one-time registration of an application with a trusted third party, wherein the trusted third party provides a seed to a first device of a first user. The first user receives and accepts a document from a second user. The first device generates the TOTP based on the seed. Using the TOTP as an encryption key, the first device computes a current hash. The delivery of the document can be validated by a second device of a second user based on a comparison of the current clock time and GPS coordinates (optional) of first device as compared to the associated values of the second device. The second device stores the document, first device's computed hash, and current clock time.