4. The seal application device of claim 1 , wherein the seal includes a barcode, of at least one dimension, that encodes the source identifier.
1. A seal application device comprising: an applicator; at least one processor; and a memory storing instructions which, when executed by the at least one processor, cause the at least one processor to perform operations comprising: determining a source user of the seal application device, the source user associated with a physical object; determining a source identifier that identifies the source user; and instructing the applicator to generate a seal that encodes the source identifier of the source user, the seal being applicable to the physical object and including a near field communication (NFC) tag that, when scanned, emits a signal carrying the source identifier, wherein the NFC tag is configured to remove the source identifier from the NFC tag in response to a first scan of the NFC tag.