We take your privacy seriously. This document briefly explains what information ZeroPrint processes in its client software and cloud services, how it is processed, and why. ZeroPrint consists of client software and a cloud-based message relay service: the client is installed on your local device and is responsible for receiving print jobs, decrypting jobs, downloading files, and completing printing; the cloud service is primarily used for authorization verification, message forwarding, and job routing.

1. Information We Process

1.1 Information Generated and Used Locally by the Client

ZeroPrint generates and uses the following information locally on your device:

• Host ID / Fingerprint: Used to identify the current device and perform authorization queries against the cloud service. This identifier is generated locally and is primarily used for authorization verification and device identification.
• Public Key: Used to enable callers to encrypt print jobs. The public key is generated locally and displayed to the user, and is typically used by the business party when making API calls.
• Private Key: Used to decrypt encrypted jobs on the local device. The private key is generated and stored only on the client locally and is never uploaded to the cloud.

1.2 Necessary Information Processed by Cloud Services

To provide authorization verification and job forwarding, the cloud service may process the following information:

• Device Identifier (Host ID / Fingerprint): Used to query authorization status.
• Print Job Metadata: Includes job ID, target printer, file URL, print parameters, callback URL, etc. The cloud service processes this information as a message relay and does not participate in the generation or interpretation of print file content.
• Callback Notification Information: After printing is completed, the client sends a result notification directly to the callback URL provided by the business party, without passing through the cloud.

1.3 Information We Do Not Actively Collect

Based on ZeroPrint's architecture design, the following content is not uploaded to the cloud as "business data" and is not actively collected or retained by us:

• Print file content
• Business body content within print jobs (if encryption mode is enabled, the cloud only receives ciphertext)
• Local private keys
• Personal identity information such as name, phone number, email, and address
• Device hardware identifiers, location information, or other personal or sensitive device information

2. How We Use This Information

The primary purposes for which ZeroPrint uses the above information include:

• Completing device authorization verification and service permission checks
• Securely forwarding print jobs to the corresponding client
• Maintaining message channels and job state transitions
• Sending print result callbacks to the business party when necessary

3. Data Transmission, Storage, and Processing

3.1 The Cloud Serves Only as a Message Relay

ZeroPrint's cloud service primarily serves the roles of "authorization verification" and "message forwarding." For print jobs themselves, the cloud does not actively parse business content, nor does it store print content as readable text on a long-term basis.

3.2 Encrypted and Plaintext Modes

Encrypted Mode: The caller may use the client's public key to encrypt print jobs. The cloud receives only ciphertext, and only the local client can decrypt and proceed with printing.

Plaintext Mode: If the caller does not use encryption, job content may pass through the cloud in plaintext form. In this case, the cloud still only forwards the message and does not retain print content as long-term data.

3.3 File Processing

Print files are downloaded directly by the client from the URL included in the job to a local temporary directory, and temporary files are cleaned up as soon as possible after printing is completed. The client performs file identification, format conversion, and printing locally, without needing to upload file content to the cloud.

4. How We Share Information

ZeroPrint does not share your print file content, local private keys, or other sensitive business content with third parties. If the business party provides a callback URL, only the necessary information required for the print result notification will be sent to that callback URL, to complete the status receipt.

5. Data Retention and Deletion

• The cloud service is not used for long-term storage of print content or file content.
• Local temporary files are cleaned up promptly after printing is completed.
• If you wish to clear local state, you may uninstall the client, delete local credentials/key entries, and clear related caches and temporary files.

6. Cookies and Similar Technologies

ZeroPrint's cloud service does not use cookies to track user behavior or conduct personalized analytics.

7. Personal Data Security

We take the following measures to protect relevant data:

• Protecting cloud communications via HTTPS
• Supporting end-to-end encryption, ensuring that print job content can only be decrypted by the local client
• Storing private keys on the local device without uploading them to the cloud
• Cleaning up local temporary files promptly after printing is completed

8. Children's Privacy

ZeroPrint does not provide services to children under the age of 13, nor does it intentionally collect personal information from children.

9. Updates to This Statement

We may update this privacy policy from time to time to reflect changes in product features, legal requirements, or security practices. Updated versions will be disclosed on the product page or through relevant release channels.

10. How to Contact Us

If you have any questions, comments, or suggestions regarding this privacy policy, please contact us through the following means:

Email: web5173@foxmail.com