Acoustic Watermark · Fingerprint · AI Detection · C2PA Provenance.
Four technologies that imprint a trusted "mark" on your audio and video content.
Certifying the provenance of your content.
Can a third party independently verify — through technical means — that a piece of audio or video is an official transmission from your organization?
As deepfakes and AI-generated audio proliferate, perceptual verification alone is no longer sufficient to determine whether content is an official transmission.
Deepfake audio of public officials circulates on social media, undermining institutional credibility and public confidence in official communications.
Broadcast content is reproduced and manipulated without authorization. Distinguishing the original from altered versions becomes operationally intractable.
Fabricated executive statements are already affecting equity valuations and corporate standing — a threat that is no longer hypothetical.
G7 Hiroshima AI Process International Code of Conduct (2023) calls for the development and deployment of watermarking and content authentication/provenance mechanisms to identify AI-generated content (Article 7).
Japan's Ministry of Internal Affairs and Communications: "Report on Ensuring the Integrity of Information Distribution in Digital Spaces" (September 2024) proposes comprehensive countermeasures against misinformation and disinformation.
Sources: G7 Hiroshima Process International Code of Conduct / MIC Study Group Report
Pre-emptive standards work better than after-the-fact denials. SIGNED SOUND lets you imprint a "this is my official content" mark on audio and video before distribution — a proactive stance against misinformation.
Source: Science Advances (2022, University of Cambridge / Google Jigsaw), among others.
A complete third-party certification workflow for audio and video — Register, Verify, Provenance, and Certify — delivered on a single cloud platform.
Imperceptibly embed proprietary acoustic watermarks into the audio track of audio and video files, register acoustic fingerprints to a tamper-evident database, and attach a C2PA-compliant SIGNED SOUND signature to the entire content — all in a single operation.
Submit content for multi-layer forensic analysis: watermark extraction, acoustic fingerprint matching, C2PA manifest verification, and AI-generated audio detection — determining with high confidence whether the content is an official transmission.
Attach C2PA (Coalition for Content Provenance and Authenticity)-compliant provenance manifests to registered content. The SIGNED SOUND signature is embedded automatically, establishing a cryptographically verifiable chain of custody.
Shachihata acts as the issuing authority for provenance certificates based on the C2PA specification. Acting as a fair third party, we certify the provenance of audio and video content — backed by Cybertrust's Certificate Authority (CA).
Register and Verify — two simple workflows to protect your content's authenticity.
Upload audio or video files to the cloud platform
Watermark embedding + fingerprint registration + C2PA provenance attachment
Download the certified file + certificate and publish
Submit the audio or video you want to verify as an official transmission
Watermark detection / Fingerprint DB matching / C2PA verification / AI audio detection
Get a detailed report with verdict and provenance chain
C2PA records hash values for the entire content — both audio and video — so even substituting just the video track while keeping the original audio is detectable as tampering. However, C2PA manifests are metadata, making them vulnerable to stripping through transcoding or re-upload. By combining Evixar's proprietary acoustic watermarking technology "EAW" (Evixar Audio Watermark) and acoustic fingerprinting technology "EFP" (Evixar Finger Print) as registered C2PA soft binding algorithms, SIGNED SOUND maintains provenance traceability from the audio signal itself even after C2PA metadata has been removed. The combination of EAW/EFP (audio layer) and C2PA (full content) delivers coverage of a variety of audio and video content scenarios. See the FAQ for details on EAW and EFP.
Acoustic watermarks are embedded directly into the audio waveform itself, while fingerprints are derived from acoustic features extracted from the waveform and stored in a database. In either case, identification is performed from the audio signal itself — surviving format conversion, re-encoding, and metadata deletion. Combined with C2PA, SIGNED SOUND provides coverage across a variety of distribution and manipulation scenarios.
Evixar's proprietary technology was selected for Japan's Ministry of Internal Affairs and Communications national program on countermeasure technologies against online disinformation — validating efficacy at the government level.
Shachihata — Japan's foremost authority on authentication and certification for over a century — now issues provenance certificates for digital content based on the C2PA specification under its institutional name.
Evixar's acoustic watermarking is the first C2PA-registered soft binding algorithm from Japan, enabling provenance tracking that persists through transcoding and re-encoding under an internationally listed standard.
Whether content was registered in advance changes what you can do when something happens. SIGNED SOUND is designed to identify whether content has been edited or altered — without stopping legitimate sharing.
Cutouts and references that help spread your content are welcome. As your signed material spreads, the mark spreads with it through cutouts and quotations. Meanwhile, fake reviews or fake ads with substituted audio show up as "not matching the official" upon verification.
Fan cutouts and reaction videos still carry the mark of the official source. AI-synthesized fake songs or "new tracks" the artist never recorded, on the other hand, lack the mark — making forgeries identifiable. The more widely known it is that official content carries a mark, the harder forgeries become to produce.
Sign and distribute press conference videos or press kits, let media use them broadly, and verify how they were used afterward. The mark persists through reporting and quotation alongside the material — so when edits distort context, you can point it out with evidence.
Register, verify, and review reports — all in one simple workflow. No technical expertise required.
Drag and drop a file to register it with the third-party certification service. Acoustic watermark, fingerprint, and C2PA provenance are applied automatically.
Upload suspicious content to trigger automatic four-layer analysis. Detects matches and tampering against registered content.
Review the overall verdict (Authentic / Partial Match / Edited / Composite / No Match), matched registered content, and a timeline visualization of detected segments. Reports can be downloaded as PDF.
Five clear verdicts — Authentic, Partial Match, Edited, Composite, No Match — summarize the result
View watermark detection and fingerprint match segments on a timeline
Download results as PDF for internal reporting or evidence preservation
Evixar is a deep-tech venture in acoustic communications, driven by the purpose of "Harnessing sound to evolve the human capacity to feel." The audio authenticity engine powering SIGNED SOUND has been independently validated across public administration, broadcasting, the film industry, and disaster prevention — and has been adopted in Japan's national disinformation countermeasure program by the Ministry of Internal Affairs and Communications (MIC) since FY2024.
Evixar's proprietary audio authentication technology was selected for Japan's national disinformation response initiative. The following proof-of-concept deployments were conducted under this program:
MIC Press Release ↗Acoustic watermarks were embedded in 7 governor's press conferences (Oct–Nov 2025) and published on YouTube. Confirmed that official content authenticity can be enhanced without significant burden on administrative workflows.
Demonstrated acoustic watermark effectiveness for IP radio broadcast content in a test environment. Proposed applications for broadcast content integrity and creator rights protection.
As an early deployment of this proprietary technology, a cross-industry standardized acoustic fingerprint database has been in production for the Japanese film sector — underpinning accessibility services including "HELLO! MOVIE" and "Caption Glasses."
Evixar's proprietary audio authenticity technology "EAF - Evixar Audio Forensics" received the Special Prize at the Tokyo Metropolitan Venture Technology Awards (Industrial Expo 2025, October 2025) — recognized for its technical innovation and societal impact. The technology is now commercialized as SIGNED SOUND through the strategic partnership between Shachihata and Evixar ↗︎.
Shachihata is the trusted brand that has upheld Japan's culture of "marking" through stamps and seals for over 100 years. The mission of "certifying through the mark" is now extended to third-party certification for audio and video content in the digital age.
"The value of a mark — analog or digital." For over 100 years, Shachihata has delivered "the value of approval and certification in the moments that matter in people's lives." A mark of commitment has connected people's trust across every contract, procedure, and act of authentication.SIGNED SOUND extends that mission to audio and video content. Even in a digital age flooded with deepfakes, the responsibility to certify official content with a "mark" and deliver the official voice — is one that Shachihata and Evixar share together.
Press Release: Shachihata × Evixar Strategic Partnership ↗
The core algorithms — EAW and EFP — are the result of over 15 years of independent research and development at Evixar, united with Shachihata's century-long mission of certifying trust. Following real-world validation through Japan's Ministry of Internal Affairs and Communications misinformation countermeasure initiative (FY2024 onwards), both companies continue to collaborate on the ongoing improvement and evolution of the service.
"Would this work for our content?" "What would implementation look like for us?" — questions like these are exactly what we're here for. Please feel free to reach out at any time.
To arrange a demonstration, discuss enterprise deployment, or request a pricing proposal, please complete the form below. Our team will respond within one business day.
