A question about privacy in creative workflows: if two unrelated services publish the same unsalted hash of an exported file, an observer can correlate those appearances even when no account name is shared. Is there a useful way to let a recipient verify integrity without creating a stable identifier for everyone who sees the file? For example, would a recipient-specific keyed MAC or a random nonce in a signed manifest meaningfully reduce correlation, and what assumptions about key distribution and file access would still matter? I am interested in the boundary between verifying a specific transfer and proving authorship or origin; neither should be assumed from a hash alone. Disclosure: I help represent Roblox Shirt Maker (https://rbxshirtmaker.com/), a browser-based clothing design project, and used AI assistance to draft this question. This is a general design question, not a claim that the project already uses these protections. Thank you.