Skip to content

Changelog

This document provides a chronological list of notable changes for each version of EncypherAI.

2.4.0 (06-28-2025)

Added

  • C2PA v2.2 Compliance: Re-architected the core package to be the reference implementation for text-based C2PA v2.2 soft binding. This includes:
  • Manifest Structure: Manifests now conform to the C2PA v2.2 specification, including the official @context, a unique instance_id, and ISO 8601 formatted timestamps.
  • Hard Binding: Added the mandatory c2pa.hash.data.v1 assertion, which contains a SHA-256 hash of the clean text content for integrity verification.
  • Soft Binding: Implemented the c2pa.soft_binding.v1 assertion, formalizing our Unicode Variation Selector method as encypher.unicode_variation_selector.v1 and linking it to a c2pa.watermarked action.
  • Advanced Signing: Integrated COSE (CBOR Object Signing and Encryption) for claims, with support for X.509 certificate validation and RFC 3161 Time-Stamp Authority (TSA) integration.
  • Conditional Hard Binding Control:
  • Introduced add_hard_binding: bool to UnicodeMetadata.embed_metadata to optionally disable hard binding, which is now the default for streaming.
  • Added require_hard_binding: bool to UnicodeMetadata.verify_metadata to allow verification of streamed content where hard binding is intentionally omitted.
  • New Internal APIs: Added _embed_c2pa_compliant and _verify_c2pa_compliant methods to encapsulate C2PA-specific logic, along with new TypedDict payload structures for all C2PA assertions.

Changed

  • Streaming Verification: The default behavior for streaming has been updated to disable hard binding. The StreamingHandler now implicitly calls embed_metadata with add_hard_binding=False to prevent false verification failures on partial content.
  • Claim Generator: The claim_generator field is now dynamically populated with the current package version (e.g., encypher-ai/2.4.0), removing the need for manual updates in future releases.

Fixed

  • StreamingHandler Initialization: Fixed a bug in the StreamingHandler where custom claims and timestamps were not being correctly passed to the embedding function, causing errors during C2PA manifest creation.
  • StreamingHandler Metadata Embedding: Fixed a critical bug in the StreamingHandler where user-supplied metadata fields (especially custom_metadata) were not being correctly preserved in the embedded payload, causing metadata round-trip verification failures in integration tests.
  • Gemini Integration Test: Fully repaired the Gemini integration test to correctly verify both non-streaming (with hard binding) and streaming (without hard binding) metadata, confirming the end-to-end workflow.
  • Core UnicodeMetadata Bugs:
  • Restored missing _bytes_to_variation_selectors and _extract_outer_payload helper methods, resolving AttributeError exceptions.
  • Corrected a critical IndentationError in unicode_metadata.py.
  • Type Checking: Fixed multiple mypy errors in the codebase:
  • Added proper null checks for COSE message payloads
  • Fixed RSA signature verification type handling
  • Added proper type annotations for timestamp requests
  • Added types-requests to development dependencies
  • Fixed string formatting of binary data
  • Added explicit string conversion for certificate common names and serial numbers

Documentation

  • Comprehensive Streaming Update: Overhauled all documentation (integration guides, README, user guides) to reflect the new require_hard_binding=False parameter for verifying streamed content.
  • C2PA Specification: Added a formal algorithm specification document (docs/c2pa_algorithm_spec.md) detailing the technical implementation for our C2PA submission.

2.3.0 (06-15-2025)

Added

  • C2PA Interoperability:
  • Introduced a new cbor_manifest metadata format for embedding full C2PA-compliant manifests serialized using CBOR. This provides a more compact and standards-aligned method for storing complex claim data.
  • Added c2pa_like_dict_to_encypher_manifest and encypher_manifest_to_c2pa_like_dict conversion utilities in encypher.interop.c2pa to seamlessly translate between Encypher's internal manifest structure and C2PA-like dictionaries.
  • Implemented conditional logic to handle both nested assertion data (for CBOR) and flattened data structures for standard JSON manifests.
  • CBOR Support:
  • Integrated the cbor2 library to enable CBOR serialization and deserialization.
  • Added helper functions for encoding/decoding CBOR payloads, including Base64 wrapping for text-based embedding.
  • Documentation & Examples:
  • Created a new example script c2pa_text_embedding_demo.py demonstrating the end-to-end flow of creating, embedding, and verifying a C2PA-like manifest.
  • Updated c2pa-relationship.md to detail the new CBOR-based manifest support and its benefits.
  • Testing:
  • Added comprehensive integration tests for C2PA and CBOR manifest round-trips, ensuring data integrity and successful verification.

Fixed

  • Documentation: Corrected all streaming verification examples across integration guides (OpenAI, Anthropic, LiteLLM, FastAPI), the README.md, and user guides to use require_hard_binding=False. This ensures documentation accurately reflects that hard binding is disabled for streamed content.
  • Type Hinting: Resolved all mypy static type checking errors in encypher.core.unicode_metadata, improving code reliability and maintainability.
  • Conversion Logic: Corrected conversion helpers to properly retain top-level timestamp and claim_generator fields during round-trip conversions.

Developer Changes

  • Refactored UnicodeMetadata to support multiple manifest formats (manifest and cbor_manifest) in both embedding and extraction workflows.

2.2.0 (06-02-2025)

Changed

  • Core Package Refactoring:
  • Split crypto_utils.py into three specialized modules:
    • keys.py: Key generation, loading, and saving functions
    • payloads.py: Payload data structures and serialization
    • signing.py: Digital signature operations
  • Renamed functions for clarity:
    • load_private_key → load_private_key_from_data
    • load_public_key → load_public_key_from_data
  • Added backward compatibility layer in crypto_utils.py that re-exports all functions and types with deprecation warnings

Added

  • Documentation:
  • Added a comprehensive Migration Guide to help users transition to the new module structure
  • Updated example scripts to use the new module imports

Developer Changes

  • Improved code organization following the Single Responsibility Principle
  • Enhanced type hints and docstrings across all modules
  • Added dedicated test file for signing functionality
  • Ensured all tests pass with the new module structure

2.1.0 (05-23-2025)

Changed

  • API Updates for UnicodeMetadata class:
    • embed_metadata:
      • Now requires signer_id as a direct parameter (replacing key_id within a metadata dictionary).
      • Accepts other metadata components (model_id, timestamp, organization, version, custom_metadata, metadata_format) as direct parameters. The generic metadata dictionary parameter has been removed for clarity and type safety.
    • verify_metadata:
      • The public_key_resolver parameter has been renamed to public_key_provider for consistency.
      • The public_key_provider function now receives signer_id as its argument.
      • Returns a tuple: (is_valid: bool, signer_id: Optional[str], payload: Union[BasicPayload, ManifestPayload, None]).
    • extract_metadata:
      • Now consistently returns a BasicPayload or ManifestPayload object (or None), rather than a raw dictionary.
  • Consistent Terminology:
    • Replaced all instances of key_id with signer_id across the API, internal logic, and documentation to better reflect its purpose.
  • StreamingHandler Update:
    • The constructor (__init__) now accepts signer_id and other metadata components as direct parameters, similar to embed_metadata.

Documentation

  • Updated all relevant documentation files, including:
    • quickstart.md
    • basic-usage.md
    • user-guide/extraction-verification.md
    • user-guide/metadata-encoding.md
    • api-reference/unicode-metadata.md
  • All examples revised to reflect the new API signatures, parameter changes, and the use of signer_id.
  • Ensured all code examples are runnable and accurately demonstrate the functionalities of version 2.1.0.

2.0.0 (04-13-2025)

Added

  • Ed25519 digital signatures for enhanced security
  • Key management utilities for generating and managing key pairs
  • Public key resolver pattern for verification
  • Improved API for metadata embedding and verification
  • Updated documentation with digital signature examples
  • C2PA-inspired manifest structure for enhanced content provenance
  • Interoperability module (encypher.interop.c2pa) for conversion between EncypherAI and C2PA-like structures
  • Comprehensive documentation on C2PA relationship and alignment

Changed

  • Replaced HMAC verification with Ed25519 digital signatures
  • Updated UnicodeMetadata class to be the primary interface
  • Deprecated MetadataEncoder and StreamingMetadataEncoder classes
  • Improved StreamingHandler to use digital signatures
  • Updated all examples and integration guides
  • Aligned manifest field names with C2PA terminology:
  • Renamed actions to assertions in ManifestPayload
  • Renamed action to label in ManifestAction
  • Renamed ai_info to ai_assertion in ManifestPayload
  • Updated documentation to reflect terminology changes
  • Enhanced docstrings with references to C2PA concepts

Security

  • Enhanced security with asymmetric cryptography
  • Separate private keys for signing and public keys for verification
  • Key ID system for managing multiple keys
  • Improved tamper detection capabilities

Documentation

  • Added new user guide: Relationship to C2PA Standards
  • Updated examples to use the new field names
  • Added code examples for the interoperability module

1.0.0 (03-22-2025)

Added

  • Initial stable release of EncypherAI
  • Core metadata encoding and decoding functionality
  • HMAC verification for tamper detection
  • Support for multiple embedding targets:
  • Whitespace (default)
  • Punctuation
  • First letter of words
  • Last letter of words
  • All characters
  • Streaming support for handling content from LLMs
  • Integration with popular LLM providers:
  • OpenAI
  • Anthropic
  • LiteLLM
  • Comprehensive documentation and examples
  • Interactive demos:
  • Jupyter Notebook demo
  • Streamlit web app
  • FastAPI example application
  • Python client library
  • JavaScript client library

Security

  • Secure HMAC verification using SHA-256
  • Secret key management for verification
  • Tamper detection capabilities