ImageSignature

 

Link to EclipseSuite BD

ImageSignature is a self-contained, highly-reliable method for tracking and verifying BD images as they move through the disc manufacturing process from authoring to final QC.

Enhanced Capability

ImageSignature Version 2.0 incorporates a new structure to better handle BD process. It provides fast layer checking capability, self-verification, and a simpler manual signature input and display. Newer versions of EclipseSuite will automatically incorporate this new signature structure.

One Signature Authoring to Replication

A key characteristic of ImageSignature is that the same signature can be derived from an image at any point in the process. Any time an image is tested with any of the EclipseSuite programs, the signature is validated and reported. The image signature validation is always performed on unencrypted or decrypted data. When decryption is required, the process is fast and automatic.

Simpler User Interface

EclipseSuite BD present the last 6 bytes (12 characters) of the 20-byte signature value to the user. This easily recognizable short form of the signature can be entered into ImageVerify when manual signature entry is necessary.

Quick Layer Check

The primary signature can be used detect layer mismatches, but only after the entire image is read. However, the new Layer Match Hash, since it contains only limited information from each layer, can report a layer mismatch almost instantly. The Layer Match Hash is created from specific, limited data from each layer that is easily and quickly accessed.

Self-verification

Since every ImageSignature 2.0 disc has its signature stored on it, ImageVerify can use that signature to validate the image integrity. This self-verification process is limited and should be used cautiously since it is somewhat self-fulfilling. Because the signature and data always stays together in the CMF, if the data is correct, the signature should always match. The self-verify rule should trigger a failure only in cases where a glass mastering formatter corrupted the data or in a case where the data cannot be read accurately by the drive. It will not detect image mixing problems (e.g. the mastering operator chose the wrong image) and should only be used if replicas are checked for mixing elsewhere in the process.

Specification Version 2.0 Signature for BD

Signature Values

In order to create a signature that remains constant through the entire manufacturing process, it is necessary to exclude certain data from the signature calculation that is known to change as the image moves through encryption and mastering. It is important to note that the excluded data does not include user data and is checked by other means during the image analysis, so image integrity is guaranteed.

ImageSignature 2.0 utilizes up to three internal 20-byte hash values and the primary signature:

  • Signature a digest of the disc information and the layer 0 and layer 1 (in case of dual layer images)

  • Layer 0 hash includes sector addresses (using PSN) and 2048 bytes of every user data sector

  • Layer 1 hash includes sector addresses (using PSN) and 2048 bytes of every user data sector

  • Layer Check hash includes specific data from 32 sectors of each layer in case of dual layer images for quick layer bonding check

Note: L1 Hash and the Layer Check Hash are not created for a single-layer image

ImageVerify Methods Using Signature

  • Verify-after-Copy

    • ImageCopy calculates signature, encrypts image, and copies to an output folder

    • ImageVerify (running inside ImageCopy) decrypts and compares output image to source signature file (same as Verification to a signature file below)

  • Verification to a Signature File

    • Signature information is read from signature file.

    • If present, signature information is compared to disc information. A mismatch is shown immediately.

    • Quick layer check is performed if dual layer. A mismatch is shown immediately in most cases.

    • The replicate is decrypted to calculate layer 0 and layer 1 (if dual layer) hashes. A mismatch is shown as soon as the layer finishes processing.

    • The signature value gets calculated from the previous information. A mismatch is shown at the end of the process.

  • Verification to a Signature Value

    • User enters the display formatted global signature value (12 characters)

    • The replicate is decrypted to calculate layer 0 and layer 1 (if dual layer) hashes.

    • The signature value gets calculated from the previous information. A mismatch is shown at the end of the process.

  • Self-Verification

    • Signature information is read from PIC data for Blu-ray.

    • Signature information is compared to disc information. A mismatch is shown right away.

    • Quick layer check is performed if dual layer. A mismatch is shown immediately in most cases.

    • The replicate is decrypted to calculate layer 0 and layer 1 (if dual layer) hashes. A mismatch is shown as soon as the layer finishes processing.

    • The signature value gets calculated from the previous information. A mismatch is shown at the end of the process.

Caution: This will test the integrity of the data, but will not detect if the image is correct.