Encryption travels with the file.
A .cc file carries encrypted document content. Authenticated chunks support streaming access and detect tampering as content is opened.
DOCUMENT PROTECTIONBUILT ON OPEN CRATE
CloseCrate.
Protected documents.
Built on an open core.
Close Crate is a document protection service built on Open Crate: encrypted files, verifiable authorship and policy-based access.
01 / THE PRODUCT
CLOSE CRATE / .ccShare the document.
Define who can open it.
For teams sharing confidential documents with clients, partners and colleagues. Package the file with its author signature and access rules.
Know who signed it.
Verify the document’s signed header, including its recipient key slots. Give recipients a verifiable author signature alongside the encrypted file.
Set the terms of access.
Define access windows and permissions through policies and signed leases. The Close Crate viewer and access service apply those rules in supported workflows.
Rust
Built for speed. Designed for reliability.
Written in Rust for native performance, ownership checks and explicit error handling.
HYBRID POST-QUANTUM CRYPTOGRAPHY
Protect today.
Prepare for
what’s next.
CLASSICALX25519 / P-256
POST-QUANTUMML-KEM-768
Classical and post-quantum cryptography, working together to protect document keys.
X25519 + ML-KEM-768
A software hybrid built with X-Wing.
P-256 + ML-KEM-768
A hardware-backed path on supported TPM devices.
How hybrid protection works
Hybrid protection is selected per key slot, not enabled by default for every file. Every sufficient path to a document key must meet the chosen protection profile. Author signatures are a separate mechanism.
About ML-KEM: NIST FIPS 203 ↗Access restrictions depend on the client and deployment. Revocation cannot take back plaintext already extracted.
02 / THE OPEN CORE
RUST / FIVE LIBRARIESOpen Crate.
A Rust core for encrypted document containers.
Build your own application around it.
01Engine
The assembly. Package content and construct container headers.
02Policy
The decisions. Evaluate access rules against supplied facts.
03Crypto
The protection. Encryption, signatures and key derivation.
04Protocol
The messages. Activation, leases and revocation.
05Format
The container’s structure. Encode, parse and verify its contents.
Build with Open Crate.
Work with Close Crate.
FOR DEVELOPERSOpen Crate
Libraries you can build with.
Five Rust libraries for containers, cryptography, protocols, access rules and packaging. Build your own application around them.
Your application supplies file access, networking, time, randomness and enforcement.
FOR DOCUMENT WORKFLOWSClose Crate
A separate document protection service.
Document viewing, access management and supported desktop integrations, offered as a separate service.
Licensing Open Crate does not include the Close Crate service. Service availability and commercial terms will be announced separately.
03 / ON THE HORIZON
CLOSE CRATE / AIIN DEVELOPMENTAI features
AI features
coming soon.
We’re building AI features and a companion service for Close Crate.
A new part of Close Crate.
Details and availability will be announced here.
04 / TRUST & USE
OPEN TO SCRUTINYAudit
the core.
Inspect the design.
Challenge the implementation.
Independent security review is next. Materials and submission details are coming soon.
INDEPENDENT AUDITS
Coming
soon.
Future audit reports and participating organizations will appear here.
No completed independent audit or participating organization is announced yet.
Use it.Inspect it.Improve it.
Open Crate Community License 1.0
Source available
FREE USE / ENTERPRISE
Free for personal non-commercial use and companies with both less than $1M annual group revenue and fewer than 25 people. Commercial licensing is required when either threshold is reached.
Existing qualifying businesses receive a 90-day transition. Employees and individual contractors count across the corporate group. Full license text will accompany the repository release; Close Crate services are separate.
QUESTIONS / ANSWERED
FOR TEAMS & DEVELOPERSBefore you build.Before you share.
What is Close Crate?
Close Crate is a document protection service in development. It combines encrypted .cc containers, author signatures and policy-based access through its viewer and access service.
What is Open Crate?
Open Crate is the reusable Rust library core for container formatting, cryptography, protocol messages, policy evaluation and packaging. Developers can build their own applications around it; Close Crate is a separate service.
Does Open Crate support post-quantum cryptography?
Open Crate supports hybrid key encapsulation using ML-KEM-768 with X25519 (X-Wing) or P-256 (MLKEM768-P256). These protect document-key access; they do not make every signature or deployment post-quantum secure. The hybrid constructions follow pinned CFRG drafts. Use of ML-KEM is not a claim of FIPS certification.
Can revocation take back a document?
Revocation can restrict subsequent access through supported clients, subject to leases and offline windows. It cannot erase plaintext already extracted or guarantee protection on a compromised device.
How will Open Crate Enterprise licensing work?
The Community License is free for personal non-commercial use and businesses with both less than $1M in annual group revenue and fewer than 25 people. Reaching either threshold requires a commercial agreement, with a 90-day transition for existing qualifying users. Close Crate is a separate service; Open Crate is source-available under the Community License.
Are the AI features available?
AI features and a companion service are in development. Availability and details will be announced here.
05 / WHAT COMES NEXT
BUILT TO BE EXPLOREDFollow the project.
Look closer at the core.
Look insideLook inside
Close Crate & Open Crate