Privacy Policy

隐私条款

Short version: Sealboard runs entirely on your device. We don't have servers, we don't collect anything, and there is no network code in the app at all.

一句话:Sealboard 完全在你设备上运行。我们没有服务器,不收集任何 数据,代码里完全没有联网逻辑。

Last updated: May 21, 2026 最后更新:2026 年 5 月 21 日

1. Summary

Sealboard ("the App") is a third-party iOS keyboard and companion app that lets you encrypt and decrypt text messages locally using standard RSA-2048 public-key cryptography. All processing happens on your device. The App does not send your data anywhere because the App contains no networking code.

2. Information We Do Not Collect

To be specific, Sealboard does not collect, transmit, sell, or share:

  • Your messages, plaintext, ciphertext, or any content you type
  • Your RSA private key, public key, or recovery mnemonic
  • Your contacts list (it lives only on your device)
  • Any personally identifiable information (name, email, phone, address)
  • Device identifiers, advertising IDs, IP addresses, or location data
  • Crash reports, telemetry, usage analytics, or diagnostic logs
  • Cookies or tracking technologies — Sealboard is not a web app

We do not use any third-party SDKs (no Firebase, no Crashlytics, no advertising networks, no analytics frameworks, nothing).

3. Information Stored on Your Device

All data needed for the App to function is stored locally in iOS sandboxed storage and never leaves your device:

  • Account: a 12-word mnemonic, your RSA-2048 public key, and your RSA-2048 private key. The private key is encrypted at rest with a symmetric key derived from your mnemonic.
  • Contacts: name + public key entries you've manually added.
  • Preferences: selected keyboard language, currently-selected contact, and similar UI state.

The keyboard extension and the main app share this data through an iOS App Group container (group.com.sealboard.app), which is also sandboxed to your device and not accessible to any other app.

4. Keyboard Extension & Full Access

iOS may prompt you to grant the Sealboard keyboard "Full Access". We request Full Access for one reason only: to read and write to the system clipboard, so the "粘贴解密 / Paste & Decrypt" feature can read incoming ciphertext and the "发送密文 / Encrypt & Send" feature can hand the encrypted output to the host app.

Even with Full Access enabled, the keyboard has no networking code. Clipboard contents are read into memory, processed locally, and never sent anywhere by us.

5. Information You May Share Yourself

Sealboard is a tool for producing ciphertext that you then choose to copy or paste into other apps (a chat app, an email, a note). Once you do that, what happens to the ciphertext is governed by the other app's privacy practices, not ours.

Your public key is, by design, safe to share — that's how RSA works. Your private key and mnemonic are not, and we provide no way to share them automatically.

6. Children's Privacy

Sealboard is not directed at children under 13. Because we collect no information from anyone of any age, no special action is needed in this regard.

7. Security

Encryption uses RSA-2048 with PKCS#1 v1.5 padding via Apple's Security framework (iOS Keychain / SecKey APIs). Mnemonic-derived AES-GCM is used to seal the on-disk account file so the private key cannot be read without the mnemonic.

Sealboard is provided as-is. RSA-2048 is a widely accepted standard today, but no encryption scheme is unbreakable forever. You are responsible for backing up your 12-word mnemonic safely — if you lose it, your account cannot be recovered by us (we have no copy).

8. Your Rights

Because we do not hold any of your data on any server, there is nothing for us to give you, delete on your behalf, or correct. To erase all Sealboard data from your device, uninstall the App. iOS will remove the App's sandboxed storage along with it.

9. Changes to This Policy

We may update this policy when the App changes — for example, if we add a feature that introduces a new permission. The "Last updated" date at the top of this page reflects the most recent revision. Material changes will be highlighted in App Store release notes.

10. Contact

Questions about this policy? Email privacy@sealboard.app.

1. 概述

Sealboard("本 App")是一款第三方 iOS 键盘 + 配套主 App,用标准的 RSA-2048 公钥密码学在本地完成文本加解密。 所有处理都在你的设备上完成。 App 不会把任何数据发到任何地方 —— 因为 App 代码里完全没有联网逻辑。

2. 我们不收集的信息

具体而言,Sealboard 不收集、不传输、不出售、不分享:

  • 你的消息、明文、密文,或你输入的任何内容
  • 你的 RSA 私钥、公钥,或助记词
  • 你的联系人列表(只存在于你的设备上)
  • 任何可识别个人身份的信息(姓名、邮箱、电话、地址)
  • 设备标识符、广告 ID、IP 地址、位置信息
  • 崩溃报告、遥测数据、使用统计、诊断日志
  • Cookies 或追踪技术 —— Sealboard 不是网页应用

我们没有集成任何第三方 SDK(没有 Firebase、没有 Crashlytics、 没有广告网络、没有分析框架,什么都没有)。

3. 设备上存储的信息

App 运行所需的全部数据都保存在 iOS 沙盒存储中,从不离开你的设备:

  • 账户:12 个英文单词的助记词、你的 RSA-2048 公钥 和私钥。私钥在磁盘上以由助记词派生的对称密钥进行 AES-GCM 加密 保存。
  • 联系人:你手动添加的姓名 + 公钥条目。
  • 偏好设置:已选语言、当前选中的联系人,以及类似的 界面状态。

键盘扩展和主 App 通过 iOS App Group 容器 (group.com.sealboard.app)共享上述数据。该容器同样 被沙盒隔离,任何其他 App 都无法访问。

4. 键盘扩展与"完全访问"权限

iOS 在你首次启用 Sealboard 键盘时会询问是否授予"完全访问"。我们 申请这个权限只有一个原因:读取和写入系统剪贴板, 这样"粘贴解密"才能拿到收到的密文、"发送密文"才能把加密结果交给 宿主聊天 App。

即使开启了"完全访问",键盘代码里依旧没有任何联网逻辑。 剪贴板内容在内存中读取、在本地处理,我们这一侧不会把它发往任何地方。

5. 你自己可能分享的信息

Sealboard 是一个生成密文的工具,你可以把生成的密文复制或粘贴到 其他 App(聊天、邮件、备忘录等)。一旦离开 Sealboard, 密文在那些 App 内的去向就受它们各自的隐私条款约束,不再由我们管辖。

你的公钥按设计就是可以公开分享的 —— 这就是 RSA 的工作方式。 私钥和助记词不能分享,我们也不提供任何自动分享它们的方式。

6. 儿童隐私

Sealboard 不针对 13 岁以下儿童。由于我们对任何年龄的用户都不收集 任何信息,这一条无需额外措施。

7. 安全

加密使用 RSA-2048 + PKCS#1 v1.5 填充,通过 Apple 的 Security 框架(iOS Keychain / SecKey API)实现。 磁盘上的账户文件用由助记词派生的密钥 AES-GCM 封装,没有助记词 就读不到私钥。

Sealboard 按"现状"提供。RSA-2048 是当前广泛接受的标准,但没有任何 加密方案能永远不可破。请妥善备份你的 12 词助记词 —— 一旦丢失, 我们无法帮你恢复账户(因为我们这里也没有副本)。

8. 你的权利

由于我们没有在任何服务器上保存你的任何数据,我们无法把数据交给你、 代表你删除或修正。要彻底清除 Sealboard 数据,卸载本 App 即可, iOS 会同时移除 App 的沙盒存储。

9. 条款变更

当 App 发生变化时(例如新增需要新权限的功能),我们可能更新本条款。 页面顶部的"最后更新"日期反映了最近一次修订。重要变更会在 App Store 的更新说明中告知。

10. 联系

对本条款有疑问?请联系 privacy@sealboard.app。