Last updated: April 5, 2026
These Terms of Service ("Terms") govern your use of the Sipher mobile application ("App") operated by Dark Castle Group, LLC ("we", "our", or "us"). By using the App, you agree to these Terms.
By creating an account or using Sipher, you agree to be bound by these Terms and our Privacy Policy. If you do not agree to these Terms, do not use the App.
You must be at least 13 years old to use Sipher. By using the App, you represent and warrant that you meet this age requirement. If you are between 13 and 18 years old, you must have parental or guardian consent to use the App. We reserve the right to request proof of age at any time and to terminate accounts that we reasonably believe belong to users under 13.
To use Sipher, you must create an account with a valid email address, username, and password. You are responsible for:
You may only create one account per person. We reserve the right to suspend or terminate duplicate accounts.
You agree not to use Sipher to:
We reserve the right to investigate and take appropriate action against anyone who violates these rules, including removing content, suspending accounts, and reporting illegal activity to law enforcement.
Sipher provides end-to-end encrypted messaging, voice notes, and media sharing. You understand and agree that:
Sipher supports voice and video calls between users. You understand and agree that:
When a call is not answered, you may choose to leave a voicemail. You understand and agree that:
Sipher allows you to post stories visible to your contacts for 24 hours. You understand and agree that:
Sipher includes interactive games that can be played with other users within a chat. You understand and agree that:
Sipher allows you to share your real-time location with specific contacts. You understand and agree that:
The Sipher AI assistant is provided for informational and conversational purposes. You understand and agree that:
Sipher offers a voice translation feature powered by third-party AI services. You understand and agree that:
Sipher includes an in-app camera with photo editing tools including filters and cropping. You understand and agree that:
Sipher offers a premium subscription ("Sipher Pro") with additional features:
You retain ownership of the content you share through Sipher. By using the App, you grant us a limited, non-exclusive license to transmit and deliver your content to intended recipients as necessary to operate the service. Due to end-to-end encryption, we cannot access or review the content of your private messages.
Sipher, including its design, logos, features, name, and code, is the intellectual property of Dark Castle Group, LLC You may not copy, modify, distribute, reverse-engineer, or create derivative works from any part of the App without our express written permission.
If you encounter content that violates these Terms (such as in stories or public-facing features), you may report it through the App. We will review reports and take appropriate action, which may include:
In compliance with applicable laws, including the TAKE IT DOWN Act, we will remove reported non-consensual intimate imagery within 48 hours of receiving a valid report.
Sipher provides tools to manage your interactions with other users:
We may suspend or terminate your account if you violate these Terms or engage in conduct that we determine is harmful to other users, the service, or third parties. You may delete your account at any time through the App settings. Upon account deletion, your data will be permanently removed from our servers within 30 days, except where retention is required by law.
Sipher is provided "as is" and "as available" without warranties of any kind, express or implied, including but not limited to implied warranties of merchantability, fitness for a particular purpose, and non-infringement. We do not guarantee uninterrupted, secure, or error-free operation of the App. We do not warrant the accuracy of AI-generated content, translations, or voicemail transcriptions.
To the fullest extent permitted by law, Dark Castle Group, LLC shall not be liable for any indirect, incidental, special, consequential, or punitive damages arising from your use of Sipher, including but not limited to damages for loss of data, loss of profits, or personal injury. Our total liability for any claim arising from or related to the App shall not exceed the amount you paid us in the 12 months preceding the claim, or $100, whichever is greater.
You agree to indemnify and hold harmless Dark Castle Group, LLC, its officers, directors, employees, and agents from any claims, damages, losses, liabilities, costs, or expenses (including reasonable attorneys' fees) arising from your use of the App, your violation of these Terms, or your violation of any rights of a third party.
Any disputes arising from or relating to these Terms or the App shall first be attempted to be resolved through informal negotiation by contacting us at support@sipherapp.com. If a dispute cannot be resolved informally within 30 days, it shall be resolved through binding arbitration in accordance with the rules of the American Arbitration Association. You agree that any arbitration will be conducted on an individual basis and not as a class action.
These Terms shall be governed by and construed in accordance with the laws of the State of California, United States, without regard to its conflict of law provisions. Any legal proceedings not subject to arbitration shall be brought in the state or federal courts located in California.
If any provision of these Terms is found to be unenforceable or invalid, that provision shall be modified to the minimum extent necessary to make it enforceable, and the remaining provisions shall continue in full force and effect.
These Terms, together with our Privacy Policy, constitute the entire agreement between you and Dark Castle Group, LLC regarding your use of Sipher and supersede any prior agreements.
We reserve the right to modify these Terms at any time. We will notify you of material changes through the App or via email at least 30 days before they take effect. Your continued use of Sipher after changes take effect constitutes acceptance of the updated Terms. If you do not agree to the updated Terms, you must stop using the App and delete your account.
If you have questions about these Terms, please contact us at: