Privacy policy · 摘自 Sotto 既有项目文档 / excerpted from existing Sotto documentation
无手机号、无邮箱、无账号、无广告。
No phone number, no email, no account, no ads.
1:1 使用 X3DH + Double Ratchet 全程 E2E；每条消息独立 DEK，删除或到期销毁密钥，正文永久不可读。
1:1 chats use X3DH + Double Ratchet end to end. Each message has an independent DEK; deleting or expiring it destroys the key and makes the plaintext permanently unreadable.
频道采用拉取式扇出：每条广播中继只存一份密文，成员数不影响写入；中继不存成员名单。签名只覆盖线上可见字段，中继保持零知识。
Channels use pull-based fan-out: the relay stores one ciphertext copy per broadcast regardless of member count, and stores no member roster. Signatures cover only wire-visible fields; the relay stays zero-knowledge.
中继侧（服务器）与设备本地是两套不同的保留期，不要合并理解：
两个已知缺口，如实写明：附件分块与自同步（SelfSync）槽目前没有自动过期时间，只能靠"接收方下载后删除"或下一次同步覆盖；若双方都不再操作，这两类密文可能长期留在中继，需运营方人工清理。
Retention on the relay and retention on your device are different. On the relay: undelivered message envelopes expire after at most 7 days and are deleted by a scheduled task; delivered envelopes are deleted as soon as the recipient acknowledges, and in any case no later than the envelope TTL (≤7 days); routing metadata is deleted together with its envelope (≤7 days); channel posts default to 24 hours and are capped at 7 days. Report material, created only when you file a report, is kept for 90 days or until the case is closed, whichever is earlier — a separate rule that never extends ordinary message retention. On your device, messages and attachments stay in the encrypted SQLCipher database until you delete the chat, delete a message, or its self-destruct timer expires; the relay's 7-day cap does not limit your local history. Known gaps: attachment chunks and SelfSync slots have no automatic expiry today and rely on recipient-side deletion or the next sync overwrite; leftover ciphertext may require manual cleanup by the operator.
中继代码不读取、不落库访客 IP 或 ASN；Cloudflare 边缘可能按平台默认策略短期保留连接日志，我们不导出、不用于画像。本版本未开启 Workers 日志观测、未接入崩溃或分析 SDK。
The relay code does not read or persist visitor IP addresses or ASNs; Cloudflare's edge may retain connection logs for a short period under its platform defaults, which we do not export or use for profiling. This build has no Workers Logs observability and ships no crash or analytics SDK.
无广告、无追踪（PrivacyInfo 声明零收集）；应用只申请收发消息、语音与通话所需的最少权限（麦克风、相机、通知），均在首次使用时询问，不读取全量相册。
No ads and no tracking (PrivacyInfo declares zero collection). The app asks only for the minimum permissions messaging, voice and calls need (microphone, camera, notifications), each at first use, and never reads the whole photo library.
门禁已强制，但抗离线暴破的下界仍是用户口令强度；协议未做第三方审计，也未与 Signal 联调。
The passphrase gate is mandatory, but resistance to offline brute force still depends on passphrase strength. The protocol has not been third-party audited and does not interoperate with Signal.