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Version: V11

About Digitally Signed Integrity Certificates in VIDIZMO

VIDIZMO provides secure, end-to-end evidence handling capabilities for law enforcement, legal, and regulatory organizations. One of the key features supporting this security is the Digitally Signed Integrity Certificate, which verifies that an evidence file remains authentic and unaltered throughout its lifecycle.

When downloading a media file from VIDIZMO, you can also optionally download its Integrity Certificate. This cryptographically signed certificate validates the file’s authenticity, ensuring that any content file can be independently verified, maintaining the chain of custody and protecting evidence integrity.

How It Works​

The Integrity Certificate mechanism builds upon VIDIZMO’s Tamper Detection capability. This feature continuously monitors media files to ensure they have not been altered after upload.

  • Evidence Upload and Encoding When a user uploads an evidence file to the VIDIZMO portal.The file undergoes an encoding workflow that transcodes it into multiple renditions (qualities) for playback across various devices.Once encoding is complete, the system downloads all renditions from storage and generates their original hash values using a Secure Hashing Algorithm (SHA).These hash values serve as unique digital fingerprints for each rendition.

  • Tamper Detection and Hash Comparison VIDIZMO stores the generated hash values in its database for future reference. During tamper detection, the system:

  • Regenerates the hash values of the stored renditions.

  • Compares these new hash values with the original ones created during ingestion.

If the hash values match, the evidence is verified as authentic and marked as Verified in the VIDIZMO Portal.If there is a mismatch, the evidence is tagged as Tampered, clearly indicating possible alteration.

For more details, refer to the article Understanding Evidence Tamper Detection.

Enabling Tamper Verification​

To generate a Digitally Signed Integrity Certificate, you must enable the Tamper Verification App in your VIDIZMO portal.This app automatically runs tamper detection workflows on all uploaded media to monitor for any unauthorized modifications, ensuring ongoing evidence integrity verification.

For more details, refer to the article How to Enable Content Tamper Detection App.

Checksum and Hash Generation​

When a file is uploaded or generated within the system:

  • A unique checksum (hash value) is created for each file using the SHA-384 cryptographic hashing algorithm.
  • Every rendition and derivative (e.g., post-redaction or clipped versions) inherits its own hash value.
  • These hash values enable tamper-proof verification across all file renditions and content-modifying activities.

This mechanism ensures a complete audit trail for sensitive content management and redaction workflows.

Digital Signature Generation​

VIDIZMO automatically generates digital signatures for all renditions within a content file upon upload completion and rendition generation.

The digital signing process:

  • Uses industry-standard cryptographic hashing algorithms (SHA-384).
  • Creates tamper-resistant verification tags for:
    • Original uploaded files
    • All generated renditions
    • Post-redaction renditions

Each rendition maintains its own digital signature, allowing granular verification of individual files. When downloading a file, you can download its Integrity Report, which includes these verification details.

Verification Process​

VIDIZMO provides a clear and straightforward verification process for validating the integrity of any content file:

  • Integrity Validation: Enables users to confirm file authenticity by comparing the current file hash with the original cryptographic signature.
  • Tamper Detection: Automatically identifies unauthorized modifications or tampering after file creation.
  • Cross-Reference Capability: Allows users to validate the current state of a file against its original signature, ensuring complete authenticity and maintaining the chain of custody.

This feature ensures that every downloaded file remains a trusted, verifiable piece of digital evidence in VIDIZMO portal. To downland the digitally signed integrity certificate refer to our article Download Digitally Signed Integrity Certificates For Evidence Integrity In VIDIZMO

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