为什么值得关注

它直接解决了孟加拉国 2024 年七月革命期间互联网被切断时人们无法通信的紧迫需求，并实现了即使在手机从未直接相遇的情况下也能工作的存储转发网状网络。

适合谁使用

身处灾难或危机地区、无网络覆盖的人群
在互联网被关闭地区活动的活动人士和抗议者
在偏远地区工作的人道主义救援人员
对网状网络和离线通信感兴趣的开发者和研究人员

典型使用场景

发送包含位置和详细信息的紧急求救信号，且优先级高于所有其他流量
通过多跳中继交换端到端加密的个人消息
查看并贡献离线社区地图，报告道路堵塞、避难所、医疗营地等信息
通过物理移动在两个断开连接的区域之间携带消息

项目优势

完全去中心化：无需服务器、互联网、SIM 卡或信号塔
支持多跳中继并显示跳数，经四节点模拟测试验证
个人聊天采用端到端加密（X25519 + AES-GCM）且密钥绑定，防止冒充
紧急求救消息优先级最高，被中继到所有其他流量之前，并触发全屏警报

使用前须知

仅支持 Android，不支持 iOS
需要授予蓝牙、附近设备和位置权限（位置信息不会发送，但 Android 强制要求用于设备发现）
无前向保密性；使用长期密钥，且紧急求救消息设计为明文

README 快速开始

Jonaki · জোনাকি

Messaging, SOS and disaster mapping that work when the network is gone.

Built for the Crisis Tech track of a hackathon honouring the July 2024 revolution in Bangladesh — when the internet was shut off and people could not reach each other.

Jonaki means firefly. One light is almost nothing; a field of them lights the way. That is the whole idea: a phone alone is useless in a blackout, but phones together carry each other's messages.

What it does

No internet. No SIM. No tower. No servers. Phones talk to each other directly over Bluetooth and Wi-Fi, and every phone relays for every other phone.

Global chat — reaches everyone the mesh can reach, including people several hops away that you were never near.
Personal chat — end-to-end encrypted. Relays carry the message but cannot read it.
SOS — one button. Sends emergency type, your location, a note and your battery level, relayed ahead of all other traffic. Full-screen alert on every phone that receives it, plus an "I'm safe" cancel.
Offline map — real street tiles bundled in the app, with community reports: road blocked, fire, shelter, medical camp, food, water, charging, danger. Reports gain confidence as other people confirm them.
Store and forward — a message with nowhere to go waits. When you walk within range of someone, it goes. Someone travelling between two cut-off areas carries messages between them without doing anything.

How the mesh works

Everything is the same envelope wearing a different costume: chat, SOS, map reports and confirmations all ride one store-and-forward pipeline.

   compose ──► sign (Ed25519) ──► store ──► offer to peers ──► relay
                                    │
                    dedup by id ────┤
                    ttl bounds hops ┤   SOS outlives its hop budget
                    expiry deletes ─┘   until it expires

When two phones meet they exchange lists of message IDs, then send only what the other is missing, highest priority first — SOS before map reports before chat.

Multi-hop is real: a message from A reaches D by being carried through B and C, and the app shows the hop count so you can see it happened.

Security, stated honestly

Every message is signed (Ed25519). Forged or altered messages are dropped and never relayed.
Personal messages are **end-to-e

July_Hackathon_Jonaki