A person in a later generation may watch footage of the Nuremberg trials. That person may also watch footage of the morning of September 11th. That person may have no method to know if the footage is real.
This is not a failure of care or media literacy. By that time, few people will remember a period when video was accepted as true by default. Distrust will not be a crisis that people fight. Distrust will be a normal condition of the world.
Why detection is not enough
The first response to synthetic media is better detection. Build a model that finds a deepfake. Ship the model. Update the model. Stay ahead of generators.
This response does not last. Each detector trains the next generation of generators to defeat it. The same pattern appears in spam filters, malware, and CAPTCHAs. Over a long period, the offense wins. A detector must be correct in every case. A generator must succeed one time. Detection can buy time. Detection cannot be the permanent answer. The permanent answer must survive generators that do not exist yet.
Prove originals instead of detecting fakes
Change the problem. Do not try to catch fake media after the fact. Sign real media at the moment of capture. Build a chain of custody for media. The chain is a continuous, checkable record from the instant of capture to the person who views the media later.
The mechanism is this. A camera or phone signs the media with a private key at the moment of recording. The signature is a mathematical proof. Hardware generates the signature. The signature is tied to that device and that time. The matching public key is registered with a neutral and verifiable authority. Any person, at any later time, can check three facts. Was this recorded by this device? Was it recorded at this time? Has it been changed since that time?
This mechanism is not speculative. The parts already exist. Apple's Secure Enclave uses a similar structure for device security. Canon ships a camera with Content Authenticity Initiative signing in the hardware. Certificate authorities and append-only public timestamping prove that something existed, without change, at a specific time. The parts are available. They are not yet assembled into a system that works at the scale of a civilization.
Signing is not magic. A stolen or compromised device can still produce a valid signature for what it records. Coercion at the point of capture is still coercion. A corrupt or captured registry is still a single point of political failure. Those failure modes are real. That is why the system must be public infrastructure. It must not be a feature of one camera application that wins in one decade. The goal is not to make lying impossible. The goal is to make authentic originals distinct from all other media, at scale, for decades.
What is at stake
Many people stop at a smaller risk. They fear that a fake video will deceive them. That risk is real. It is not the main cost.
The main cost is the last hundred years of footage. That footage was recorded before a signing standard existed. It will sit next to a large volume of new media that is unsigned and unverifiable. The unsigned past does not keep a special status as trustworthy. It enters the same set of doubt as the rest. The risk is not only future deception. The risk is a later collapse of confidence in everything that came before.
The proposal
The needed system is not hard to describe. It is hard to build.
A public signing standard that no single vendor controls. Device manufacturers that put the standard in hardware by default. The feature must not sit as an optional setting. A registration authority structured as a public utility: accountable, neutral, and permanent. The authority must not be a consortium of companies with commercial incentives on the board.
The Content Authenticity Initiative, with support from Adobe, the BBC, and Microsoft, is a real effort. It deserves credit for that. A vendor consortium is still not the same as public infrastructure. Certificate authorities and DNS work because their structure can survive the interests of one company. Media provenance needs the same structure, at the same scale, with the same seriousness.
Limits
Cryptographic provenance does not solve every problem with media.
It does not prove that the scene in front of the camera was not staged. It does not prove that a person who appears in the frame consented. It does not restore trust in unsigned archives by itself. It only answers a narrower question: does this file match a signed capture from a registered device at a stated time, without later change?
That narrower answer is still valuable. Courts, newsrooms, and public records need it. Without it, those institutions lose a shared method to separate an authentic original from a synthetic substitute.
The time window
Return to the person who watches that footage decades from now. That person may be uncertain whether any of it is real. The difference between that world and a world with a checkable signature is being set now. The systems built in the next several years matter more than systems that wait for several decades.
The cost of delay rises each year. More unsigned media enters the pile. Fewer people remember a world where video was trustworthy by default. The people who remember that condition are still alive. That is not a nostalgic claim. It is the reason this generation has the standing to build the system that preserves a checkable record for the people who come after.