[

{

"identifier": 1,

"alg": "com.digimarc.validate.1",

"type": "watermark",

"decodedMediaTypes": [

"audio",

"video",

"text",

"image"

],

"entryMetadata": {

"description": "Digimarc Validate Digital Watermarking algorithm",

"dateEntered": "2024-05-17T17:00:00.000Z",

"contact": "info@digimarc.com",

"informationalUrl": "https://www.digimarc.com/products/digital-content-authentication"

}

},

{

"identifier": 2,

"alg": "org.atsc.a336",

"type": "watermark",

"decodedMediaTypes": [

"audio",

"video",

"image"

],

"entryMetadata": {

"description": "ATSC watermarking (A/334, A/335, A/336)",

"dateEntered": "2024-05-17T15:43:00.000Z",

"contact": "atsc@atsc.org",

"informationalUrl": "https://www.atsc.org/atsc-documents/a3362017-content-recovery-redistribution-scenarios/"

}

},

{

"identifier": 3,

"alg": "io.iscc.v0",

"type": "fingerprint",

"decodedMediaTypes": [

"text",

"image",

"audio",

"video",

"application"

],

"entryMetadata": {

"description": "ISO 24138 - International Standard Content Code (ISCC) V0 algorithm",

"dateEntered": "2024-05-17T16:00:00Z",

"contact": "info@iscc.io",

"informationalUrl": "https://ieps.iscc.codes/iep-0020/"

}

},

{

"identifier": 4,

"alg": "com.adobe.trustmark.Q",

"type": "watermark",

"decodedMediaTypes": [

"image"

],

"entryMetadata": {

"description": "Adobe Trustmark variant Q",

"dateEntered": "2024-05-17T17:00:00.000Z",

"contact": "collomos@adobe.com",

"informationalUrl": "https://github.com/adobe/trustmark/"

}

},

{

"identifier": 5,

"alg": "com.adobe.trustmark.C",

"type": "watermark",

"decodedMediaTypes": [

"image"

],

"entryMetadata": {

"description": "Adobe Trustmark variant C",

"dateEntered": "2024-05-17T17:00:00.000Z",

"contact": "collomos@adobe.com",

"informationalUrl": "https://github.com/adobe/trustmark/"

}

},

{

"identifier": 6,

"alg": "com.adobe.icn.dense",

"type": "fingerprint",

"decodedMediaTypes": [

"image"

],

"entryMetadata": {

"description": "Adobe Image Comparator Network Dense Fingerprint",

"dateEntered": "2024-05-17T17:00:00.000Z",

"contact": "collomos@adobe.com",

"informationalUrl": "https://openaccess.thecvf.com/content/CVPR2021W/WMF/html/Black_Deep_Image_Comparator_Learning_To_Visualize_Editorial_Change_CVPRW_2021_paper.html"

}

},

{

"identifier": 7,

"alg": "ai.steg.api",

"type": "watermark",

"decodedMediaTypes": [

"image",

"video",

"application"

],

"entryMetadata": {

"description": "Steg.AI invisible watermarking",

"dateEntered": "2024-05-20T10:50:00.000Z",

"contact": "info@steg.ai",

"informationalUrl": "https://openaccess.thecvf.com/content_CVPR_2019/papers/Wengrowski_Light_Field_Messaging_With_Deep_Photographic_Steganography_CVPR_2019_paper.pdf"

}

},

{

"identifier": 8,

"alg": "ai.trufo.pawprint.watermark",

"type": "watermark",

"decodedMediaTypes": [

"image",

"audio",

"video"

],

"entryMetadata": {

"description": "PawPrint neural watermarking for images, audio, and video. Imperceptible, with a 44/88 bit payload robust to compression, cropping, rotation, splicing, time/space scaling, common filters, and moderate AI transformations.",

"dateEntered": "2024-08-14T15:00:00.000Z",

"contact": "support@trufo.ai",

"informationalUrl": "https://trufo.ai/watermarks"

},

"softBindingResolutionApis": [

"https://c2pa.trufo.ai/v1"

]

},

{

"identifier": 9,

"alg": "ai.trufo.pawprint.fingerprint",

"type": "fingerprint",

"decodedMediaTypes": [

"image",

"audio",

"video"

],

"entryMetadata": {

"description": "PawPrint neural fingerprinting for images, audio, and video. Generates a perceptual content signature that can be registered in or queried against Trufo's federated provenance ledgers for content matching and attribution.",

"dateEntered": "2024-08-14T15:00:00.000Z",

"contact": "support@trufo.ai",

"informationalUrl": "https://trufo.ai/watermarks"

},

"softBindingResolutionApis": [

"https://c2pa.trufo.ai/v1"

]

},

{

"identifier": 10,

"alg": "app.overlai.watermark.1",

"type": "watermark",

"decodedMediaTypes": [

"image"

],

"entryMetadata": {

"description": "Overlai Watermark version 1",

"dateEntered": "2024-08-14T16:00:00.000Z",

"contact": "luke@overlai.app",

"informationalUrl": "https://overlai.app/watermark"

}

},

{

"identifier": 11,

"alg": "tv.kinetiq.watercast.48.1",

"type": "watermark",

"decodedMediaTypes": [

"video"

],

"entryMetadata": {

"description": "Teletrax Watermarking algorithm",

"dateEntered": "2024-10-16T17:00:00.000Z",

"contact": "c2pa@kinetiq.tv",

"informationalUrl": "https://kinetiq.tv/broadcasting-syndication/"

}

},

{

"identifier": 12,

"alg": "castLabs.watermark.1",

"type": "watermark",

"decodedMediaTypes": [

"video",

"image",

"audio"

],

"entryMetadata": {

"description": "castLabs Single Frame Forensic Watermarking",

"dateEntered": "2024-11-13T12:00:00.000Z",

"contact": "info@castlabs.com",

"informationalUrl": "https://castlabs.com/image-watermarking/"

}

},

{

"identifier": 13,

"alg": "com.adobe.trustmark.P",

"type": "watermark",

"decodedMediaTypes": [

"image"

],

"entryMetadata": {

"description": "Adobe Trustmark variant P",

"dateEntered": "2025-02-05T17:00:00.000Z",

"contact": "collomos@adobe.com",

"informationalUrl": "https://github.com/adobe/trustmark/"

}

},

{

"identifier": 14,

"alg": "com.imatag.lamark.v1",

"type": "watermark",

"decodedMediaTypes": [

"image"

],

"entryMetadata": {

"description": "Imatag invisible watermarking for images",

"dateEntered": "2025-02-26T15:00:00.000Z",

"contact": "c2pa@imatag.com",

"informationalUrl": "https://www.imatag.com/digital-watermarking/"

}

},

{

"identifier": 15,

"alg": "com.nagra.nexguard.watermark.1",

"type": "watermark",

"decodedMediaTypes": [

"video",

"audio",

"image"

],

"entryMetadata": {

"description": "NAGRA NexGuard Watermarking with Single Frame Detection Capability",

"dateEntered": "2025-02-26T13:53:25.000Z",

"contact": "gabriel.cantin@nagra.com",

"informationalUrl": "https://nagra.vision/security-solutions/forensic-watermarking/"

}

},

{

"identifier": 16,

"alg": "com.mentaport.watermark.1",

"type": "watermark",

"decodedMediaTypes": [

"video",

"audio",

"image"

],

"entryMetadata": {

"description": "Mentaport Watermarking Engine",

"dateEntered": "2025-03-12T13:00:00.000Z",

"contact": "hello@mentaport.com",

"informationalUrl": "https://docs.mentaport.xyz"

}

},

{

"identifier": 17,

"alg": "com.digicaps.fingerprint.1",

"type": "fingerprint",

"decodedMediaTypes": [

"image"

],

"entryMetadata": {

"description": "DigiCAP Fingerprint Engine",

"dateEntered": "2025-06-16T17:00:00.000Z",

"contact": "info.bornid@digicaps.com",

"informationalUrl": "https://docs.bornid.io"

}

},

{

"identifier": 18,

"alg": "com.sonicorigin.watermark.1",

"type": "watermark",

"decodedMediaTypes": [

"audio",

"video"

],

"entryMetadata": {

"description": "SonicOrigin Watermarking Engine",

"dateEntered": "2025-08-13T18:25:00.000Z",

"contact": "info@sonicai.ai",

"informationalUrl": "https://sonicai.ai"

}

},

{

"identifier": 19,

"alg": "com.microsoft.invismark.1",

"type": "watermark",

"decodedMediaTypes": [

"image",

"video"

],

"entryMetadata": {

"description": "Microsoft Responsible AI InvisMark",

"dateEntered": "2025-10-12T18:25:00.000Z",

"contact": "rai_provenance@microsoft.com",

"informationalUrl": "https://arxiv.org/abs/2411.07795"

}

},

{

"identifier": 20,

"alg": "com.microsoft.wavmark.1",

"type": "watermark",

"decodedMediaTypes": [

"audio",

"video"

],

"entryMetadata": {

"description": "Microsoft Responsible AI WavMark",

"dateEntered": "2025-10-12T15:00:00.000Z",

"contact": "rai_provenance@microsoft.com",

"informationalUrl": "https://arxiv.org/abs/2308.12770"

}

},

{

"identifier": 21,

"alg": "ai.contentlens.image.basewmk",

"type": "watermark",

"decodedMediaTypes": [

"image"

],

"entryMetadata": {

"description": "ContentLens Image Watermarking (Base)",

"dateEntered": "2025-11-26T14:30:00.000Z",

"contact": "team@contentlens.ai",

"informationalUrl": "https://api.contentlens.tech/docs"

}

},

{

"identifier": 22,

"alg": "ai.contentlens.image.ensemblewmk",

"type": "watermark",

"decodedMediaTypes": [

"image"

],

"entryMetadata": {

"description": "ContentLens Image Watermarking (Ensemble)",

"dateEntered": "2025-11-26T14:30:00.000Z",

"contact": "team@contentlens.ai",

"informationalUrl": "https://api.contentlens.tech/docs"

}

},

{

"identifier": 23,

"alg": "ai.contentlens.image.customwmk",

"type": "watermark",

"decodedMediaTypes": [

"image"

],

"entryMetadata": {

"description": "ContentLens Image Watermarking (Custom)",

"dateEntered": "2025-11-26T14:30:00.000Z",

"contact": "team@contentlens.ai",

"informationalUrl": "https://api.contentlens.tech/docs"

}

},

{

"identifier": 24,

"alg": "ai.contentlens.audio.mono",

"type": "watermark",

"decodedMediaTypes": [

"audio"

],

"entryMetadata": {

"description": "ContentLens Audio Watermarking (Mono)",

"dateEntered": "2025-11-26T14:30:00.000Z",

"contact": "team@contentlens.ai",

"informationalUrl": "https://api.contentlens.tech/audio/docs"

}

},

{

"identifier": 25,

"alg": "ai.contentlens.audio.stereo",

"type": "watermark",

"decodedMediaTypes": [

"audio"

],

"entryMetadata": {

"description": "ContentLens Audio Watermarking (Stereo)",

"dateEntered": "2025-11-26T14:30:00.000Z",

"contact": "team@contentlens.ai",

"informationalUrl": "https://api.contentlens.tech/audio/docs"

}

},

{

"identifier": 26,

"alg": "es.lumatrace",

"type": "watermark",

"decodedMediaTypes": [

"image"

],

"entryMetadata": {

"description": "Java-native Adaptive Spatial Watermarking using Blue-channel injection. Reference implementation (v4.0) with Cloud Soft-Binding API",

"dateEntered": "2026-01-26T17:30:00.000Z",

"contact": "contact@lumatrace.es",

"informationalUrl": "https://github.com/Cyrah2R/lumatrace-cloud"

}

},

{

"identifier": 27,

"alg": "com.markany.watermark.1",

"type": "watermark",

"decodedMediaTypes": [

"image",

"video",

"audio"

],

"entryMetadata": {

"description": "MarkAny invisible watermarking with robustness against cropping, resizing, and compression",

"dateEntered": "2026-02-25T00:00:00.000Z",

"contact": "c2pa@markany.co.kr",

"informationalUrl": "https://en.markany.com/contentssecurity"

}

},

{

"identifier": 28,

"alg": "com.verimatrix.watermark.1",

"type": "watermark",

"decodedMediaTypes": [

"video"

],

"entryMetadata": {

"description": "Verimatrix watermarking algorithm: provides an essence-based forensic watermarking mechanism that may be used as a C2PA soft-binding technology. The algorithm embeds an imperceptible identifier payload directly into the audiovisual signal, enabling persistent association between a media asset and an external provenance record or manifest reference even when file-level cryptographic bindings are broken by transcoding, re-packaging, streaming workflows, or other common transformations. The embedded payload is designed to be robust against compression and typical distribution modifications and can be recovered from derivative copies via blind extraction without requiring access to the original master file. This supports C2PA soft-binding requirements by enabling downstream verification and traceability through extraction of a durable identifier that can be resolved to provenance or distribution metadata maintained outside the media file",

"dateEntered": "2026-02-26T14:16:00.000Z",

"contact": "c2pa@verimatrix.com",

"informationalUrl": "https://www.verimatrix.com/c2pa/watermarking/"

}

},

{

"identifier": 29,

"alg": "com.writerslogic.zwc-watermark.1",

"type": "watermark",

"encodedMediaTypes": [

"text/plain",

"text/markdown",

"text/html"

],

"entryMetadata": {

"description": "WritersLogic CPOP zero-width character (ZWC) watermark for text content. Embeds a truncated HMAC-SHA256 tag as zero-width Unicode characters (U+200B, U+200C, U+200D, U+FEFF) at deterministic word-boundary positions selected via HMAC-seeded Fisher-Yates shuffle. The tag binds the document content hash and Merkle Mountain Range root to the authorship evidence chain, enabling blind extraction without access to the original. Robust against copy-paste and re-encoding; invalidated by content modification (by design, as content changes require re-attestation). Part of the CPOP proof-of-process authorship attestation system implementing draft-condrey-cpop-protocol",

"dateEntered": "2026-03-18T20:00:00.000Z",

"contact": "david@writerslogic.com",

"informationalUrl": "https://docs.writerslogic.com/soft-binding/zwc-watermark"

}

},

{

"identifier": 30,

"alg": "com.aiwatermark.videoseal.1",

"type": "watermark",

"decodedMediaTypes": [

"video"

],

"encodedMediaTypes": [

"video/mp4",

"video/webm"

],

"entryMetadata": {

"description": "Neural video watermarking using Meta FAIR's VideoSeal model, providing perceptually invisible soft-binding watermarks in video content. Supports MP4/WebM. Integrates with C2PA manifest resolution via the AIWatermark Soft Binding Resolution API",

"dateEntered": "2026-03-08T00:00:00.000Z",

"contact": "jonathan@aiwatermark.com",

"informationalUrl": "https://aiwatermark.com/algorithms/videoseal-v1"

},

"softBindingResolutionApis": [

"https://aiwatermark.com/api/v1"

]

},

{

"identifier": 31,

"alg": "com.aiwatermark.pixelseal.1",

"type": "watermark",

"decodedMediaTypes": [

"image"

],

"encodedMediaTypes": [

"image/png",

"image/jpeg",

"image/webp"

],

"entryMetadata": {

"description": "Neural image watermarking using Meta FAIR's PixelSeal model, providing perceptually invisible soft-binding watermarks in image content. Embeds a 256-bit payload robust to common image transformations. Integrates with C2PA manifest resolution via the AIWatermark Soft Binding Resolution API",

"dateEntered": "2026-03-08T00:00:00.000Z",

"contact": "jonathan@aiwatermark.com",

"informationalUrl": "https://aiwatermark.com/algorithms/pixelseal-v1"

},

"softBindingResolutionApis": [

"https://aiwatermark.com/api/v1"

]

},

{

"identifier": 32,

"alg": "com.aiwatermark.audioseal.1",

"type": "watermark",

"decodedMediaTypes": [

"audio"

],

"encodedMediaTypes": [

"audio/mpeg",

"audio/wav",

"audio/flac",

"audio/mp4"

],

"entryMetadata": {

"description": "Neural audio watermarking using Meta FAIR's AudioSeal model, providing imperceptible soft-binding watermarks in audio content. Supports localized detection of watermarks within audio segments. Integrates with C2PA manifest resolution via the AIWatermark Soft Binding Resolution API",

"dateEntered": "2026-03-08T00:00:00.000Z",

"contact": "jonathan@aiwatermark.com",

"informationalUrl": "https://aiwatermark.com/algorithms/audioseal-v1"

},

"softBindingResolutionApis": [

"https://aiwatermark.com/api/v1"

]

},

{

"identifier": 33,

"alg": "eu.sasha.softbinding.v1",

"type": "watermark",

"decodedMediaTypes": [

"image"

],

"encodedMediaTypes": [

"image/jpeg",

"image/png",

"image/webp"

],

"entryMetadata": {

"description": "Invisible watermarking technology for image and video assets, enabling C2PA manifest recovery and content provenance verification after metadata stripping or transcoding.",

"dateEntered": "2026-04-16T00:00:00.000Z",

"contact": "contact@sasha.eu",

"informationalUrl": "https://sasha.eu/technology"

}

},

{

"identifier": 34,

"alg": "ai.verda.watermark.image.1",

"type": "watermark",

"decodedMediaTypes": [

"image"

],

"encodedMediaTypes": [

"image/png",

"image/jpeg",

"image/avif"

],

"entryMetadata": {

"description": "VerdaAI invisible image watermarking",

"dateEntered": "2026-04-16T00:00:00.000Z",

"contact": "harsha@verda.ai",

"informationalUrl": "https://verda.ai/watermarking"

}

},

{

"identifier": 35,

"alg": "ai.verda.watermark.video.1",

"type": "watermark",

"decodedMediaTypes": [

"video"

],

"encodedMediaTypes": [

"video/mp4",

"video/webm",

"video/quicktime"

],

"entryMetadata": {

"description": "VerdaAI invisible video watermarking",

"dateEntered": "2026-04-16T00:00:00.000Z",

"contact": "harsha@verda.ai",

"informationalUrl": "https://verda.ai/watermarking"

}

},

{

"identifier": 36,

"alg": "ai.verda.watermark.audio.1",

"type": "watermark",

"decodedMediaTypes": [

"audio"

],

"encodedMediaTypes": [

"audio/mpeg",

"audio/wav",

"audio/aac",

"audio/ogg",

"audio/flac"

],

"entryMetadata": {

"description": "VerdaAI invisible audio watermarking",

"dateEntered": "2026-04-16T00:00:00.000Z",

"contact": "harsha@verda.ai",

"informationalUrl": "https://verda.ai/watermarking"

}

},

{

"identifier": 37,

"alg": "com.evixar.eaw.1",

"type": "watermark",

"decodedMediaTypes": [

"audio",

"video"

],

"entryMetadata": {

"description": "EAW (Evixar Audio Watermark) is an audible-range audio watermarking algorithm developed by Evixar Inc. Embeds and extracts a soft binding identifier for C2PA manifest recovery.",

"dateEntered": "2026-04-24T00:00:00.000Z",

"contact": "c2pa@evixar.com",

"informationalUrl": "https://www.evixar.com/en/technology/eaw/"

}

},

{

"identifier": 38,

"alg": "com.evixar.efp.type3.1",

"type": "fingerprint",

"decodedMediaTypes": [

"audio",

"video"

],

"entryMetadata": {

"description": "EFP Type 3 (Evixar Finger Print Type 3) is an audio fingerprinting algorithm developed by Evixar Inc. Extracts a soft binding identifier from registered content via fingerprint matching for C2PA manifest recovery.",

"dateEntered": "2026-04-24T00:00:00.000Z",

"contact": "c2pa@evixar.com",

"informationalUrl": "https://www.evixar.com/en/technology/efp/"

}

},

{

"identifier": 39,

"alg": "com.cognitive-proof.vsrmark.1",

"type": "watermark",

"decodedMediaTypes": [

"text"

],

"entryMetadata": {

"description": "VSRMark hides a structured byte payload inside visible Unicode text by appending invisible Variation Selectors after visible characters. Each hidden byte maps to one variation selector. The payload is wrapped in a block containing a magic identifier (VSR1), version number, payload length, and CRC32 checksum.",

"dateEntered": "2026-06-04T00:00:00.000Z",

"contact": "support@cognitive-proof.com",

"informationalUrl": "https://github.com/Cognitive-Proof/VSRMark"

}

},

{

"identifier": 40,

"alg": "me.deepmark.audio.vigil.128",

"type": "watermark",

"decodedMediaTypes": [

"audio"

],

"entryMetadata": {

"description": "Vigil is a 128-bit-per-second neural audio watermarking algorithm developed by DeepMark Inc. Real-time capable on both CPU and GPU. Embedding can be performed by the demo DeepMark ingestion API at https://ingestion-api.deepmark.me. NOTE: This is a demo/playground deployment that signs manifests with test certificates, so manifest signatures will not validate against any trust authority.",

"dateEntered": "2026-06-05T00:00:00Z",

"contact": "hello@deepmark.me",

"informationalUrl": "https://www.deepmark.me"

},

"softBindingResolutionApis": [

"https://resolution-api.deepmark.me"

]

},

{

"identifier": 41,

"alg": "com.writerslogic.text-fingerprint.1",

"type": "fingerprint",

"encodedMediaTypes": [

"text/plain",

"text/markdown",

"text/html"

],

"entryMetadata": {

"description": "WritersLogic CPoE robust text fingerprint. Computes a 256-bit SimHash over overlapping character 4-grams of normalized text and records the hex-encoded value as a fingerprint-type soft binding for manifest recovery. Normalization applies Unicode NFC, removes zero-width and formatting characters (U+200B, U+200C, U+200D, U+FEFF, U+2060, variation selectors U+FE00-U+FE0F), lowercases, collapses whitespace, and strips punctuation, so the fingerprint is unchanged by reformatting, re-encoding, case and whitespace edits, and zero-width-character injection. Character 4-grams keep a single-word edit local, so the fingerprint stays stable even on short, one-sentence text. The document is additionally split into overlapping 512-character windows (50% overlap) that are each fingerprinted, recorded as scoped blocks (start, length) alongside the whole-document block, so an extracted excerpt or truncated copy can be matched against a window block. Two fingerprints match when their Hamming distance is at most 32 bits (12.5%), identifying the same content under light edits. Robust to edits and formatting but not to paraphrase. Part of the CPoE proof-of-effort authorship attestation system implementing draft-condrey-cpoe-protocol.",

"dateEntered": "2026-06-22T00:00:00.000Z",

"contact": "david@writerslogic.com",

"informationalUrl": "https://docs.writerslogic.com/soft-binding/text-fingerprint"

}

},

{

"identifier": 42,

"alg": "com.writerslogic.zwc-watermark.2",

"type": "watermark",

"encodedMediaTypes": [

"text/plain",

"text/markdown",

"text/html"

],

"entryMetadata": {

"description": "Revision of com.writerslogic.zwc-watermark.1. Embeds an HMAC-SHA256 routing tag as zero-width Unicode characters at deterministic word-boundary positions selected via an HMAC-seeded Fisher-Yates shuffle, binding the document content hash and Merkle Mountain Range root for blind extraction. Changes from version 1: the symbol alphabet drops U+FEFF (a byte-order-mark hazard) for U+200B, U+200C, U+200D, and U+2060, consistent with the fingerprint normalization; and the tag is protected by a Reed-Solomon erasure code spread across surplus positions, so extraction recovers from partial loss of the zero-width characters instead of failing all-or-nothing. Robust to copy-paste and re-encoding; invalidated by content modification by design. Part of the CPoE proof-of-effort authorship attestation system implementing draft-condrey-cpoe-protocol.",

"dateEntered": "2026-07-07T00:00:00.000Z",

"contact": "david@writerslogic.com",

"informationalUrl": "https://docs.writerslogic.com/soft-binding/zwc-watermark-v2"

}

},

{

"identifier": 43,

"alg": "com.writerslogic.text-structure.1",

"type": "fingerprint",

"encodedMediaTypes": [

"text/plain",

"text/markdown",

"text/html"

],

"entryMetadata": {

"description": "WritersLogic CPoE structural text fingerprint. Computes a deterministic, model-free 256-bit SimHash over a document's structural skeleton rather than its content words, so it survives light synonym substitution that changes wording while preserving sentence and token lengths. From NFC-normalized text (zero-width and formatting characters removed, sentence and paragraph boundaries and punctuation preserved) it derives the sentence-length sequence, the paragraph-length sequence, the punctuation-class profile, and the closed-class (function-word) skeleton, and folds these weighted features into the hash. Because the features are model-free the value is reproducible by any verifier. Two fingerprints match when their Hamming distance is at most 24 bits (about 9 percent). Robust to light, length-preserving synonym substitution, reformatting, re-encoding, and zero-width-character injection; not robust to substantive lexical paraphrase (which alters sentence or token lengths), heavy restructuring, or translation. Part of the CPoE proof-of-effort authorship attestation system implementing draft-condrey-cpoe-protocol.",

"dateEntered": "2026-07-07T00:00:00.000Z",

"contact": "david@writerslogic.com",

"informationalUrl": "https://docs.writerslogic.com/soft-binding/text-structure"

}

},

{

"identifier": 44,

"alg": "com.writerslogic.text-minhash.1",

"type": "fingerprint",

"encodedMediaTypes": [

"text/plain",

"text/markdown",

"text/html"

],

"entryMetadata": {

"description": "WritersLogic CPoE lexical MinHash text fingerprint for excerpt and quotation matching. Over text normalized with Unicode NFC, casefolding, zero-width and formatting-character removal, whitespace collapse, and punctuation stripping, it computes a 128-value MinHash signature of word 5-gram shingles using a fixed seeded permutation family, and records 32-band by 4-row locality-sensitive-hashing band hashes as sublinear lookup keys. Estimated Jaccard set-overlap identifies the same or overlapping content at a Jaccard of 0.70 or above, so a copied paragraph or a reordered or partially deleted passage matches its source even when whole-document fingerprints diverge. Deterministic; interoperable with ISO 24138 (ISCC) Text-Code semantics. Robust to reordering, minor deletion, and reformatting; not robust to paraphrase. Part of the CPoE proof-of-effort authorship attestation system implementing draft-condrey-cpoe-protocol.",

"dateEntered": "2026-07-07T00:00:00.000Z",

"contact": "david@writerslogic.com",

"informationalUrl": "https://docs.writerslogic.com/soft-binding/text-minhash"

}

},

{

"identifier": 45,

"alg": "io.blockfact.audio.watermark.32",

"type": "watermark",

"decodedMediaTypes": [

"image"

],

"entryMetadata": {

"description": "BlockFact invisible image watermarking for provenance. Embeds a 32-bit lookup key derived from the on-chain registration hash, enabling C2PA manifest recovery via the BlockFact Soft Binding Resolution API.",

"dateEntered": "2026-07-10T16:00:00.000Z",

"contact": "egbert@blockfact.io",

"informationalUrl": "https://blockfact.io"

},

"softBindingResolutionApis": [

"https://api.blockfact.io/api/soft-binding/v1"

]

},

{

"identifier": 46,

"alg": "com.doverunner.watermark.1",

"type": "watermark",

"decodedMediaTypes": [

"video"

],

"entryMetadata": {

"description": "DoveRunner's forensic watermarking solution delivers invisible, tamper-resilient traceability into video content — from enterprise distribution pipelines to end-consumer playback",

"dateEntered": "2026-07-27T14:00:00.000Z",

"contact": "c2pa@Doverunner.com",

"informationalUrl": "https://docs.doverunner.com/content-security/"

}

},

{

"identifier": 47,

"alg": "com.writerslogic.text-watermark-semantic.1",

"type": "watermark",

"encodedMediaTypes": [

"text/plain",

"text/markdown",

"text/html"

],

"entryMetadata": {

"description": "WritersLogic CPoE post-hoc semantic embedding watermark for paraphrase- and translation-robust manuscript identification. Applies key-conditioned dual-embedding watermarking: the text is revised post-generation via semantic-preserving lexical substitutions selected to align the document's contextual sentence-level and token-level embedding representations with a secret-key-derived watermark direction in the shared embedding space. Detection requires only the secret key and the candidate text; a one-sided hypothesis test on the dot product of the extracted dual embedding against the watermark direction determines presence or absence at a calibrated false-positive rate. The secret key is never embedded in the text and is not disclosed during verification. Robust to paraphrase, translation, format conversion, re-encoding, and zero-width-character injection, because the signal is anchored in the semantic embedding space rather than in surface characters or token statistics. Not robust to complete rewriting that substantially changes meaning. Works on any existing text without generation-time access; applicable to both AI-generated and human-authored content. Part of the CPoE proof-of-effort authorship attestation system implementing draft-condrey-cpoe-protocol.",

"dateEntered": "2026-07-28T00:00:00.000Z",

"contact": "david@writerslogic.com",

"informationalUrl": "https://docs.writerslogic.com/soft-binding/text-watermark-semantic"

}

},

{

"identifier": 48,

"alg": "com.joinmonolith.sha256",

"type": "fingerprint",

"decodedMediaTypes": [

"image",

"video",

"audio",

"text",

"application"

],

"entryMetadata": {

"description": "Monolith SHA-256 content fingerprint for C2PA manifest recovery",

"dateEntered": "2026-07-29T00:00:00.000Z",

"contact": "contact@joinmonolith.com",

"informationalUrl": "https://docs.joinmonolith.com/guide/fingerprinting"

},

"softBindingResolutionApis": [

"https://api.joinmonolith.com/api/c2pa"

]

},

{

"identifier": 49,

"alg": "com.museblossom.contentsdefence.1",

"type": "watermark",

"decodedMediaTypes": [

"audio",

"image",

"video"

],

"entryMetadata": {

"description": "Contents Defence invisible image watermark, used to recover the associated C2PA manifest when embedded metadata is absent.",

"dateEntered": "2026-08-10T00:00:00.000Z",

"contact": "contact@museblossom.com",

"informationalUrl": "https://museblossom.com/about"

}

},

{

"identifier": 50,

"alg": "me.reconize.videoseal.1",

"type": "watermark",

"decodedMediaTypes": [

"image",

"video"

],

"entryMetadata": {

"description": "Reconize deployment of the VideoSeal invisible watermark (Meta AI open research), embedding a 256-bit identity payload into image and video pixels via on-device Core ML. Used by the Reconize Mac app (C2PA conformant Generator Product) to bind C2PA manifests to pixels so provenance survives metadata stripping.",

"dateEntered": "2026-08-10T00:00:00.000Z",

"contact": "hello@reconize.me",

"informationalUrl": "https://reconize.me/softbinding.html"

}

},

{

"identifier": 51,

"alg": "io.diker.sigi.v1",

"type": "watermark",

"decodedMediaTypes": [

"image"

],

"entryMetadata": {

"description": "Sigi invisible watermarking engine by Okeanos B.V.",

"dateEntered": "2026-08-11T00:00:00.000Z",

"contact": "support@diker.io",

"informationalUrl": "https://diker.io/sigi"

}

},

{

"identifier": 52,

"alg": "com.adobe.hiermark.A",

"type": "watermark",

"decodedMediaTypes": [

"audio"

],

"entryMetadata": {

"description": "Adobe Hierarchical Audio watermark (HierMark) variant A",

"dateEntered": "2026-08-13T12:00:00.000Z",

"contact": "collomos@adobe.com",

"informationalUrl": "https://helpx.adobe.com/uk/creative-cloud/apps/adobe-content-authenticity/content-credentials/overview.html"

}

},

{

"identifier": 53,

"alg": "com.adobe.flowmark.A",

"type": "watermark",

"decodedMediaTypes": [

"video"

],

"entryMetadata": {

"description": "Adobe FlowMark video watermarking variant A",

"dateEntered": "2026-08-13T12:00:00.000Z",

"contact": "collomos@adobe.com",

"informationalUrl": "https://arxiv.org/abs/2607.05261"

}

},

{

"identifier": 54,

"alg": "be.immostory.videoseal.1",

"type": "watermark",

"decodedMediaTypes": [

"video"

],

"encodedMediaTypes": [

"video/mp4"

],

"entryMetadata": {

"description": "ImmoStory AI deployment of Meta FAIR's Video Seal 1.0 invisible video watermark. Embeds a 256-bit payload (64-bit public ImmoStory constant + 192-bit per-video identifier) into every AI-generated property video before C2PA signing; the identifier resolves to the video's original C2PA manifest so provenance survives re-encoding and metadata stripping (EU AI Act Art. 50(2) second marking layer).",

"dateEntered": "2026-10-12T00:00:00.000Z",

"contact": "support@immostory.ai",

"informationalUrl": "https://immostory.ai/en/provenance"

}

},

{

"identifier": 55,

"alg": "com.adobe.trustmark.F",

"type": "watermark",

"decodedMediaTypes": [

"image"

],

"entryMetadata": {

"description": "Adobe FiLMCAM Conditional Access Watermarking / Trustmark variant F",

"dateEntered": "2026-10-14T14:00:00.000Z",

"contact": "collomos@adobe.com",

"informationalUrl": "https://github.com/adobe/trustmark/"

}

},

{

"identifier": 56,

"alg": "com.quatvision.quatmark.1",

"type": "watermark",

"decodedMediaTypes": [

"image"

],

"encodedMediaTypes": [

"image/jpeg",

"image/png",

"image/tiff",

"image/webp"

],

"entryMetadata": {

"description": "QuatMark keyed invisible image watermark. The watermark carries a compact record identifier bound to the asset's C2PA Manifest in the QuatMark manifest repository; QuatVision resolves the identifier back to the signed manifest when the manifest has been stripped from the file. Generator product on the C2PA Conforming Products List (Level 1, September 2026).",

"dateEntered": "2026-10-16T00:00:00.000Z",

"contact": "info@quatvision.ai",

"informationalUrl": "https://quatmark.com/en/products/c2pa-content-credentials"

}

},

{

"identifier": 57,

"alg": "com.encypher.text.watermark.1",

"type": "watermark",

"decodedMediaTypes": [

"text"

],

"entryMetadata": {

"description": "Encypher text watermark. Embeds an invisible identifier in signed text without changing how the text renders. The identifier can be recovered from the full text, from a copied excerpt of sufficient length, or from lightly edited text, and Encypher resolves it to the C2PA Manifest for that text, including when the embedded manifest has been removed.",

"dateEntered": "2026-10-19T00:00:00.000Z",

"contact": "c2pa@encypher.com",

"informationalUrl": "https://encypher.com/c2pa/soft-binding/text-watermark"

}

},

{

"identifier": 58,

"alg": "com.encypher.text.fingerprint.1",

"type": "fingerprint",

"decodedMediaTypes": [

"text"

],

"entryMetadata": {

"description": "Encypher text content fingerprint. SHA-256 of the Unicode NFC-normalized visible text, computed before any Encypher marks or the embedded C2PA Manifest are added. Used to look up the C2PA Manifest for an exact copy of signed text.",

"dateEntered": "2026-10-19T00:00:00.000Z",

"contact": "c2pa@encypher.com",

"informationalUrl": "https://encypher.com/c2pa/soft-binding/text-fingerprint"

}

},

{

"identifier": 60,

"alg": "studio.aidr.silentcipher.1",

"type": "watermark",

"decodedMediaTypes": [

"audio"

],

"encodedMediaTypes": [

"audio/wav"

],

"entryMetadata": {

"description": "AIDR Studio deployment of Sony Research's open SilentCipher 44.1 kHz audio watermark (silentcipher 1.0.5, MIT), used without retraining. Embeds a 40-bit payload (public AIDR brand byte 0xAD + 32-bit per-clip identifier issued by AIDR's watermark register) into every AI-generated speech clip before C2PA signing; the identifier resolves to the clip's original C2PA manifest in AIDR's register, so provenance survives sample-rate conversion, re-encoding and metadata stripping (EU AI Act Art. 50(2) second marking layer).",

"dateEntered": "2026-10-28T00:00:00.000Z",

"contact": "info@aidr.studio",

"informationalUrl": "https://aidr.studio/provenance/watermark/"

},

"softBindingResolutionApis": [

"https://aidr.studio/api/c2pa/v1"

]

},

{

"identifier": 61,

"alg": "com.etchv.watermark.1",

"type": "watermark",

"decodedMediaTypes": [

"image"

],

"encodedMediaTypes": [

"image/jpeg",

"image/png",

"image/webp",

"image/tiff",

"image/gif"

],

"entryMetadata": {

"description": "Etchv invisible image watermark carrying a 256-bit per-file identifier, embedded before C2PA signing. The manifest's c2pa.soft-binding assertion holds the identifier (base64 of its 32 bytes), and the identifier resolves to that manifest through Etchv's public Soft Binding Resolution API, so provenance can be recovered after metadata is stripped. Only files their owner opted in to public provenance resolve.",

"dateEntered": "2026-10-28T20:00:00.000Z",

"contact": "security@etchv.com",

"informationalUrl": "https://etchv.com/docs/guides/content-credentials"

},

"softBindingResolutionApis": [

"https://api.etchv.com/c2pa/v1"

]

}

]