Changes to the DCI specification

[Leo Enticknap]

DCI has released a new revision of the Digital Cinema System Specification to the DCI website. Digital cinema System Specification v1.5.0

Changes in v1.5.0 since v1.4.5: Deletes mandate for the SMS to collect post-show playout log reports from Media Blocks within 24 hours. Deletes mandate for the SMS and OMB to implement SMPTE ST 430-17 SMS-OMB Communications Protocol. Deletes SMS security-related requirements (certificate, TLS, AuthorityID). Removes requirement for a display device to have physical lock(s). Removes references to HD-SDI interface. Update to DRM events Table 21. Fixes broken links to the Glossary.

See the Digital Cinema System Specification section of the DCI Website for full details.

Does this mean that the requirement for tamper switches ("Removes requirement for a display device to have physical lock(s)" and certificates maintained in volatile RAM ("Deletes SMS security-related requirements (certificate, TLS, Authority ID") are going away? If so, this is a big win for exhibitors, and I hope that the equipment makers will quickly come out with new firmware that ignores tamper switches and does not brick ICPs and media blocks if their batteries go flat.

I guess I'll have to read the revised document to answer my own questions, but don't have time right now. Will try to over the weekend if no-one beats me to it.

[Caleb Williams]

Going through the red line document these are some quick takeaways;

Playback logs are no longer required to be collected every 24 hours by the sms from the security manager. Legacy log generation can be used where necessary

SMS or TMS is no longer required to use TLS, authID, or DCI compliant digital certificate to communicate with SM

Playout log specification removed

Electronic monitoring of Secure processing block is still required, but logging of the AuthID of the user that performed the projector and SPB marriage is no longer required. Only the "marriage" and "marriage break" events are logged.

SMS messaging to MB Security managers is no longer required to follow SMPTE ST 470-17, but it is still "encouraged" via operational messages.

Requirement for physical locks on projector SPB enclosures is rescinded, but tamper evident seals are still required. Eg, tape, holographic

Added reference to "movie pack integrity data", that lack of which will cause a termination of playout

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Basically, they didn't change anything to do with the secure identity requirements of your playback server, they just made the requirements for systems that communicate with the security manager less strict. I could be wrong, but I believe this applies to theater management software like Screenwriter, and even the web interface components of an IMB, which are logically separate from the secure media block that actually decrypts data.

They also broadened the secure processing block enclosure requirements, so projector manufacturers are no longer required to use physical "skeleton keys", but can instead use some sort of logical or software process to clear tamper events. That does not remove the requirement for physical tamper switches, just the mechanism that secures the enclosure.

[Marcel Birgelen]

tl;dr...

But, according to our AI:

Version 1.5.0 has not softened any of these requirements. If anything, it has been refined (e.g., adding FIPS 140-3 as an option, adding direct view display SPB requirements). The core model remains: devices must have hard physical enclosures with 24/7 tamper detection (battery-backed), and upon any breach detection, all cryptographic secrets are automatically and irrecoverably destroyed. Log records, notably, are not purged — only the keys are zeroized.

This primarily seems to concern log collection for audit purposes. I guess since there are ZERO Virtual Print Fee contracts left, this requirement is no longer relevant for any stakeholder.

[Steve Guttag]

What surprises me on this is that if a theatre is suspected of mischievous operations (unauthorized shows, for whatever the reason), the audit logs are proof-positive that the shows ran on that equipment and what content was run. I would presume that the visual and audio watermarking are still present for the unauthorized duplication stuff.

[Bruce Cloutier]

Yeah, I would be completely surprised if anyone, on anything, backed off on any security restrictions. The general security industry keeps recommending larger key sizes which can no longer be accommodated by some devices. This is a case where more security is less as it forces plain text communications.

I can see dropping some of the logging if those logs no longer serve as proof. e.g. They can be faked/modified.

I have no idea what the DCI certification process is like. Maybe these things cannot be easily verified and they are cutting their certification costs?

[Leo Enticknap]

Basically, they didn't change anything to do with the secure identity requirements of your playback server...

I should have guessed that DCI was never going to do anything that would reduce costs and/or eliminate drags on productivity to the end user/exhibitor!

[Marcel Birgelen]

I should have guessed that DCI was never going to do anything that would reduce costs and/or eliminate drags on productivity to the end user/exhibitor!

If it happens, then it was more of an accident.

But I guess that the manufacturers have pushed for this change, as it saves them some implementation headaches in future updates.

[Mark Gulbrandsen]

Aside from logs, now projectors also have keystone adjustment... They wouldn't allow that on S1 or S2...

[Jim Cassedy]

"Changes To the DCI Specification"
. . . at least they didn't add more aspect ratios!

[James Gardiner]

This is interesting.

Recent ISDCF notes on next-generation cinema — looking 10+ years out — seem to indicate a growing mindset around reducing complexity and cost, particularly in security implementation and hardware. This appears to be driven by a combination of shorter theatrical windows and the prevailing narrative of attendance contraction in certain markets.

DCI-compliant projectors remain capital-intensive, and I suspect future screen counts will be directly influenced by their cost, especially as replacement cycles and expansion decisions are reassessed.

Reading between the lines, there may be cost-containment motivations behind this directional shift. Whether these ideas translate into meaningful, practical savings — or simply reallocate cost and complexity elsewhere — remains to be seen.

[Caleb Williams]

This is interesting.

Recent ISDCF notes on next-generation cinema — looking 10+ years out — seem to indicate a growing mindset around reducing complexity and cost, particularly in security implementation and hardware. This appears to be driven by a combination of shorter theatrical windows and the prevailing narrative of attendance contraction in certain markets.

DCI-compliant projectors remain capital-intensive, and I suspect future screen counts will be directly influenced by their cost, especially as replacement cycles and expansion decisions are reassessed.

Reading between the lines, there may be cost-containment motivations behind this directional shift. Whether these ideas translate into meaningful, practical savings — or simply reallocate cost and complexity elsewhere — remains to be seen.

I mean they didn't make THAT many changes. But likewise, I remain hopeful that costs will come down. The biggest changes are the logs and the TMS<->SMS communication spec. I doubt you'll see many projector manufacturers make changes to interlock switches just because of their low cost of implementation and simplicity.

I wish theater owners had a heavier seat at the table when it comes to changes to DCI spec.