Hello,
here my idea specially against deep fakes.
1. Introduction
In a digital world where sharing multimedia files such as videos, music, images and voice messages is commonplace, the need for authentication, confidentiality and integrity of these files is becoming increasingly important. A robust system that ensures that files cannot be tampered with or modified by unauthorized third parties becomes essential. OpenPGP (Open Pretty Good Privacy) offers a proven model that is already used to sign and encrypt emails and files. In this concept, OpenPGP is to be adapted to sign and optionally encrypt multimedia files.
2. Objectives
Ensuring integrity: The recipient can ensure that the received file is unaltered and authentic.
Authentication: The creator of the file can be verified through digital signatures.
Confidentiality: The file can be encrypted so that only authorized recipients can decrypt and view/listen to it.
Traceability and copyright protection: Digital signatures protect the author and prove the authenticity of the content.
3. Using OpenPGP for multimedia files
3.1. Key pair
Similar to the standard OpenPGP approach, two keys are used:
Private key: Used by the author of the file to digitally sign it. It is not shared publicly and remains secret.
Public key: Distributed to the public so that others can verify the signature or encrypt files for the author.
For encrypting multimedia content, the Diffie-Hellman key exchange method can be used to securely exchange the symmetric key between the parties.
3.2. Signing and encryption
Signing: The author signs the file with his private key to ensure that the recipient recognizes the file as authentic and unaltered.
Encryption (optional): The creator can encrypt the file with the recipient's public key, so that only the recipient can decrypt it with their private key.
3.3. EXIF metadata for images
For images, it is proposed to store the signature in the EXIF metadata, which is already widely used for information such as camera data, location and date. A new EXIF field type, e.g. "crypto signature", could be standardized. This would contain the digital signature of the image file.
Example of an EXIF field:
Tag: "crypto signature"
Content: The OpenPGP signature of the image.
The signature could include all image data as well as the existing metadata to prevent tampering. Any change to the image data or the metadata would invalidate the signature.
3.4. Signing videos, music and voice messages
For other file types such as videos, music and voice messages, the signature could be stored directly in the file, similar to email signatures. Alternatively, a separate signature file (.sig) could be provided and distributed along with the media file.
For videos, container formats such as MP4 could be extended with an optional field to store the signature.
For music files (e.g. MP3, FLAC), similar container extensions could be provided.
Voice messages could be signed in formats such as OGG or WAV.
3.5. Format suggestion for EXIF and metadata fields
In addition to existing RFC standards for EXIF and metadata, a new field for digital signatures could be specified as follows:
Tag name:
Code:
EXIF:CryptoSignature
Tag type: Binary (the digital signature)
Signature algorithm: OpenPGP (RSA/DSA with SHA-256)
Public key reference: Optionally, a field could be included that refers to the public key used (e.g. a URL or a key hash).
4. Example workflow
4.1. Creation of a signed image file
The creator creates an image (e.g. JPEG).
He signs the image with his private key. The signature is stored in the EXIF metadata under the tag
Code:
EXIF:CryptoSignature
.
Optionally, the image is encrypted with the recipient's public key.
The signed image is transmitted or published.
4.2. Verification of the signature by the recipient
The recipient receives the image and extracts the EXIF metadata.
He uses the author's public key to verify the signature.
If the signature is valid, the file is authentic and unchanged. If not, the file may have been tampered with.
5. Benefits
Security: OpenPGP-based signatures and encryption provide a strong security guarantee.
Flexibility: Both signing and encryption can be combined optionally and depending on the use case.
Trustworthiness: Filesn can be uniquely authenticated, protecting copyright and preventing tampering.
Backward compatibility: EXIF metadata for images and separate signature files for other formats ensure that older systems continue to work.
6. Challenges and open questions
Standardization of the EXIF signature: The new EXIF field for the crypto signature needs to be standardized to ensure compatibility with existing tools.
Storage requirements: The signatures can slightly increase the file size, especially for large files.
Key management: Managing key pairs (private and public) can be challenging for less technical users.
7. Conclusion
Using OpenPGP to sign and optionally encrypt multimedia files provides a proven method to ensure the authenticity, integrity and confidentiality of content. By integrating signatures into EXIF metadata for images and adapting multimedia containers for other file types, a secure and flexible infrastructure for file sharing can be created.
8. Use cases and scenarios
Using OpenPGP to sign and encrypt multimedia files can be used in a variety of real-world scenarios. Some of the key use cases are:
8.1. Copyright protection for artists
Musicians, photographers and video artists can digitally sign their works to protect and prove their authorship. This is especially important in an era of mass distribution and potential copyright infringement.
Musicians: A musician could release a new piece of music that is digitally signed. This way, fans can be sure that the file is authentic and has not been altered.
Photographers: A photographer can sign any image, ensuring that it is theirs and has not been tampered with. The signature could be stored in the EXIF metadata to allow easy authentication.
Video creators: When distributing videos across different platforms, signing can ensure that the video remains in its original form.
8.2. Secure corporate communications
Companies can sign and encrypt internal videos, voice recordings or images to ensure that only authorized employees can access them and the integrity of the files is guaranteed.
Secure video instructions: A company could ensure that only authorized employees can view certain training videos or confidential recordings by signing and encrypting them.
Secure audio messages: In security-critical industries such as the military or aviation, audio messages could be encrypted and signed to ensure that they are authentic and only accessible to the intended recipient.
8.3. Distribution of sensitive media files
Media companies or political organizations that publish sensitive data or videos could encrypt and sign them to ensure that they are not tampered with or intercepted.
Journalists: Journalists could sign videos or audio recordings from confidential sources to ensure their integrity and show that the recordings have not been altered.
Whistleblowers: Similar to secure documents, whistleblowers could sign their recordings to ensure that they have not been compromised or tampered with by third parties.
8.4. Artworks and NFTs
In the area of non-fungible tokens (NFTs) and digital artworks, OpenPGP could provide an additional level of authentication by signing artworks and their digital certificates.
NFTs: Digital artworks could not only be signed as NFTs, but also with an additional OpenPGP signature that ensures their authenticity and integrity.
9. Technical implementation
9.1. Integration into existing tools
The integration of OpenPGP signatures and encryption into existing multimedia workflows and tools could be done through plug-ins or extensions. Possible integration points include:
Image editing software: Tools such as Photoshop or GIMP could integrate functions for signing and encrypting images in the EXIF metadata.
Music software: Music editing tools such as Audacity could introduce options for digitally signing audio files.
Video editing: Programs such as Adobe Premiere or DaVinci Resolve could offer functions for signing videos, either within the container or as a separate signature file.
9.2. Open source libraries
There are already a number of open source libraries for integrating OpenPGP. These could serve as a basis for implementing signing and encryption in multimedia files.files.
GnuPG (GPG): One of the most popular implementations of OpenPGP. GnuPG could be extended to support the specific requirements for multimedia files such as embedding signatures in EXIF data.
Libgcrypt: A cryptography library used in conjunction with GnuPG could be adapted for encryption and signing.
9.3. Public key distribution
One challenge in implementing this system is the distribution of public keys. This could be done in several ways:
Public keyservers: Artists, companies or other users could host their public keys on existing keyservers (similar to what happens with email communication).
Integrated key distribution: For specialized applications, public keys could be distributed directly via platforms or digital marketplaces (e.g. in the context of NFTs or artist platforms).
9.4. Verification of signatures
The verification of signatures could be done by simple tools or browser-based applications that load the multimedia files, read the EXIF metadata and verify the digital signature. Similar to emails signed by PGP, a visual confirmation of the signature could be displayed in multimedia players or image viewers.
10. Future outlook
The integration of OpenPGP in the signing and encryption of multimedia files could have far-reaching effects on various industries. In the future, the following developments could occur:
Standardization: New RFCs could be specified to regulate the exact implementation of EXIF signatures and containers for other file types.
Platform integration: Large platforms such as YouTube, Spotify or social media could provide native support for signed and encrypted files to simplify the verification of content.
Blockchain and PGP: In combination with blockchain technologies, OpenPGP signatures could be used as an additional level of authentication for digital assets or works of art.
11. Conclusion
Extending the use of OpenPGP to multimedia files offers a promising way to ensure authenticity, integrity and confidentiality in the digital world. Signing and optionally encrypting videos, music, images and voice messages can ensure that the creator of the file is clearly verified and the file remains protected from unauthorized access or manipulation. The introduction of EXIF metadata for signatures and customizations in existing container formats could pave the way for a safer and more trustworthy distribution of digital content.
12. Fighting deepfakes through digital signatures
Deepfakes, generated through the use of artificial intelligence (AI), are an increasingly threatening form of digital manipulation. These technologies make it possible to falsify videos, audio files and images to represent people or events that do not correspond to reality. To address this challenge, digital signatures based on OpenPGP could become an effective means of combating deepfakes.
12.1. Challenges posed by deepfakes
Deepfakes are problematic because they make it difficult to distinguish between real and fake content. This has potentially serious consequences in many areas:
Politics: Manipulated videos could be used to propagate false political statements or actions.
Media: False content could be spread in news or social media to undermine public trust in official reports.
Individual harm: Individuals could become victims of reputational damage or blackmail through fake videos or images.
12.2. Digital signatures as a countermeasure
Digital signatures as described in this concept could provide robust protection against deepfakes. When images, videos or audio files are signed, the recipient can ensure that the content comes from the specified source and has not been altered since it was signed. This would make it significantly more difficult to pass off manipulated content as authentic.
12.2.1. Authenticating the source
If the creator of original content (e.g. a media outlet or celebrity) uses a digital signature, the recipient could easily verify the authenticity of the content:
Media outlets: News channels could ensure that all their published content is digitally signed so that any recipient can authenticate the source and be sure that the material has not been altered.
Celebrities or politicians: In an era where fake videos and statements from well-known personalities are a big problem,r, digital signatures could be used to ensure the authenticity of their video or audio statements. False content could be immediately detected and exposed.
12.2.2. Trust networks
Another approach to combating deepfakes would be to build trust-based networks. Each signed file would be signed not only by the creator, but also by trusted third parties to confirm its authenticity. This could be done by organizations or independent auditors who validate content.
Media trust networks: A system in which media files are signed by several trusted organizations could ensure that fake or manipulated content can be quickly detected and traced.
Verification by independent auditors: External auditors could review videos, images or audio content and confirm with their signature that the files are authentic and unadulterated. This would immediately expose deepfakes as manipulated because they would not be signed by official auditors.
12.3. Detecting deepfakes
In addition to using digital signatures, a combination of AI-based deepfake detection algorithms and PGP signatures could be an effective strategy. The AI would automatically check the content for potential tampering, while the signature ensures that the original creator is authenticated.
AI detection: Algorithms trained to detect deepfakes could analyze suspicious image or video content and determine if it has been tampered with.
Signature validation: After analysis, the system could verify the digital signature. If the file is not properly signed or the signature does not match, the system could raise an alarm.
12.4. Encryption as additional protection
In addition to signing, encrypting multimedia files could help prevent deepfakes in certain scenarios by making the content accessible only to specific recipients. This could be particularly useful when dealing with confidential content that is not intended for the public:
Encrypted video instructions: In security-critical areas, video messages could be encrypted to ensure that they can only be viewed by authorized recipients and are not tampered with or distributed.
Confidential content: Encrypted content could ensure that private conversations or confidential voice messages are not tampered with or misused as deepfakes.
12.5. Blockchain in combination with PGP
One possible future perspective for combating deepfakes could be the combination of OpenPGP with blockchain technology. Blockchain-based systems provide an immutable, transparent register that makes changes to files traceable. In combination with OpenPGP, the steps of file creation, signing and distribution could be clearly recorded, providing an additional layer of security.
Immutable history: Storing the file history in a blockchain could ensure that the origin and any modification of the file can be traced.
PGP transactions: Every signing or verification of files could be recorded as a transaction in the blockchain. This would allow recipients to check at any time when and by whom a file was signed.
13. Technological requirements for the fight against deepfakes
13.1. Extensions to multimedia formats
The existing multimedia formats would need to be further developed to efficiently integrate digital signatures. New standards should:
Make room for signatures, e.g. in the metadata of videos, images and audio files.
Ensure that the signatures are easily verifiable without having to change the content itself.
Be compatible with existing tools to ensure broad acceptance.
13.2. Education and user training
For digital signatures to be effective against deepfakes, users must be informed and trained about the need and use of these signatures:
Media consumers: They should know how to verify signed content and recognize when a file is not properly signed.
Content creators: They need to be trained on how to sign their content and maintain its authenticity.
13.3. Automated signature verification tools
Automated tools could be developed to simplify signature verification. These could:
Automatically verify the signature of a piece of content as soon as it is downloaded or streamed.
Display warnings when a piece of content is unsigned or contains an invalid signature.
Provide user-friendly integrations, e.g. in web browsers, media players or social media.
14. Conclusion: A robust first response to deepfakes
The threat posed by deepfakes requires innovative and robust solutions. Digital signatures based on OpenPGP offer a way to ensure the integrity and authenticity of multimedia content and prevent its manipulation. By integrating signatures into multimedia files, distributing public keys and building trust networks, content can be effectively protected against counterfeiting.
In combination with AI-based detection algorithms and possible blockchain solutions, a strong system for combating deepfakes is created that restores trust in digital content and limits the spread of misinformation.
15. Legal framework and regulation
The introduction of digital signatures to combat deepfakes and secure multimedia content could be supported by appropriate legal frameworks. Since deepfakes often encounter not only technical but also legal problems, cooperation between technology and legislation is required.
15.1. Regulation of deepfakes
Many countries are already considering laws to restrict the use of deepfake technologies or punish their misuse. Digital signatures could play a key role in legislation by providing a technical basis for verifying content. Possible approaches include:
Requirement to label digital content: Legal regulations could stipulate that all media content created, especially in sensitive areas such as politics or news, must be digitally signed to ensure authenticity.
Prosecution of misuse of deepfakes: In cases where deepfakes are used for fraud, defamation or other crimes, digital signatures could serve as proof that the manipulated content does not come from the authentic source.
15.2. Protection of intellectual property
Digital signatures could play an important role in the legal framework of intellectual property protection. They could be used to ensure that the rights of creators, artists and rights holders are protected. Some possible legal measures include:
Legally binding signatures: Digital signatures could serve as clear proof of authorship or ownership of a piece of content in a legal framework. This would give creators the ability to more easily prosecute infringements.
Contract-based use: Signed files could play a central role in licensing agreements or other legal documents to ensure that the original files are authentic and used in the creator's spirit.
15.3. Regulation by platforms
Online platforms such as social networks, media sites and content sharing services could be required to distribute content only if it has been digitally signed by the creators. This could help significantly limit the spread of deepfakes:
Automatic signature verification: Platforms could check content for digital signatures upon publication and prioritize signed content. Unsigned or invalidly signed content could be flagged or blocked.
Increased transparency: Platforms could indicate to users whether a piece of content is digitally signed and inform them of the origin and authenticity of the content. This would increase transparency and help users to detect manipulative content.
15.4. Data protection and copyright
Data protection and copyright issues need to be considered in connection with the use of digital signatures. Since the encryption of content and authentication through signatures involve the processing of personal data, certain principles must be upheld:
Data protection-compliant implementation: Signatures should be designed in such a way that they do not disclose unnecessary personal data. This could be achieved, for example, by pseudonymizing or anonymizing the signature key.
User rights: Authors and rights holders should have clear rights regarding the management and control of their digital signatures to ensure that their content is used in accordance with their wishes.
16. Implementation challenges
Although digital signatures are a powerful tool to combat deepfakes and protect multimedia content, there are also implementation challenges that need to be considered.
16.1. Complexity of the infrastructure
The introduction of a system in which multimedia files can be signed and verified worldwide requires a comprehensive technical infrastructure. This must be both robust and user-friendly to ensure widespread acceptance.
Global acceptance: Since digital content is often consumed across borders, there must be a global standardization of signature and verification technologies. This means that standards must be developed that are internationally recognized and accepted.
Interoperability: The technologies used must be able to be integrated into different platforms and tools to ensure that signed content is universally verifiable. This requires cooperation between software providers, platforms and developers of cryptosystems.
16.2. Ease of use
The implementation of digital signatures must also be simple and understandable for end users. Many people are not familiar with the use of cryptographic tools, which could make acceptance difficult.
Automated processes: The signing of files and their verification should be automated as much as possible to make it easier for users to use.
User interfaces: Media players, image viewers and platforms should offer intuitive interfaces that show users the authenticity of content without them having to understand technical details.
16.3. Potential for abuse
Like any technology, the use of digital signatures could be abused. There is a risk that criminals could create fake signatures or exploit vulnerabilities in the cryptosystems.
Protection against fake signatures: Systems must be developed to ensure that signatures cannot be forged. This could be secured by using hardware security modules (HSM) or other advanced cryptographic methods.
Responsibility of platforms: Platforms must be able to quickly identify potentially dangerous or manipulated content and act accordingly.
17. Summary and conclusion
The use of OpenPGP to sign and encrypt multimedia content offers a comprehensive approach to securing the authenticity and integrity of digital media. In the fight against deepfakes and digital manipulation, this technology could play a crucial role in increasing trust in digital content.
Authenticity and integrity: Digital signatures make it possible to reliably check content for its authenticity and authenticity. They protect against manipulation and misuse by deepfakes.
Wide applicability: The technology could be used in a variety of industries, from media production to politics, secure communication and intellectual property protection.
Challenges and solutions: There are still some technical and organizational challenges, but by combining innovative technologies, legal frameworks and user-friendly implementations, a secure and trustworthy system for digital content can be created.
Overall, the combination of cryptographic signatures with modern technologies such as AI and blockchain offers the potential to effectively combat deepfakes and ensure a secure digital future.
Best Regards,
Jan Bludau
Signing and encrypting is good. OpenPGP is probably not the most relevant tool for this particular purpose.
Sony, Nikon and Canon have already come together to address authentication with the Content Authenticity Initiative’s (CAI) C2PA digital signature system which appears to be based on X.509/PKIX. I have not read the specs in depth but looks like they started with CMS.
Unless the technical approach the industry has picked is completely broken, this area has passed the point where IETF could add value by putting an alternative on the table. We would make matters worse.
Where we might add value is in binding individual objects into some form of generic append-only Merkle-Tree authenticated notary log infrastructure.
The area where current IETF work might add value is in the encryption space and it is possible that might be something MOQ ends up taking a look at. But again, OpenPGP is not really the tool I would start with. OpenPGP is designed to encrypt large globs of monolithic data. If you are encrypting single JPG files, it works. But the whole point of MOQ is that you want to be able to chop streams up into parts and dip into them in non-linear fashion without having to grab the whole thing.
To add value, a 'multimedia' encryption format really has to be optimized to the content domain and the bulk of the work there is in understanding the content domain and working out which parts are metadata that a service needs to understand and which parts are content that should be end to end encrypted. While OpenPGP could be extended to support that sort of thing, the result wouldn't be OpenPGP.
The hard work in this area is being done by MOQ. Adding encryption would require some form of key agreement that covers a complete MOQ package and then applying it to individual chunks of data inside the package by generating a separate key/IV through some KDF. The scheme I would pick for that is OCB which supports streaming and does not fail catastrophically through nonce reuse. We couldn't use that for OpenPGP because three people had overlapping patent claims. We can do it now though.
On Sat, Oct 19, 2024 at 8:59 AM Jan Bludau <bludau.it.services@xxxxxxxxx> wrote:
