Methods and systems for electronic document authentication are disclosed. In one aspect, a method of generating an electronic postmark includes receiving, via a server, a request message from an electronic network, the request message comprising request data including payload data and meta data, generating a timestamp in response to receiving the message, hashing the payload data to generate a payload hash, digitally signing the metadata, the payload hash, and the timestamp to generate a digital signature, generating a response message, the response message generated to comprise the metadata, the payload hash, the timestamp, and the digital signature; and transmitting the response message onto the electronic network.

In certain embodiments, cryptographic-chain-based verification of postage transaction records may be facilitated. In some embodiments, a customer computer system may obtain a customer private key associated with a customer from a secure local storage at the customer computer system. The customer computer system may obtain (i) a first vendor digital signature derived from a first postage transaction record and (ii) a second postage transaction record. The customer computer system may create a customer digital signature based on (i) the customer private key, (ii) the first vendor digital signature, and (iii) the second postage transaction record. The customer computer system may provide the customer digital signature to a vendor computer system associated with the postage vendor, and, in response, obtain a second vendor digital signature from the vendor computer system, wherein the second vendor digital signature is based on (i) a vendor private key associated with the postage vendor and (ii) the customer digital signature.