connecting...
aes-256-gcm encrypted • ecdh p-521 key exchange
you can share your id with others to connect privately
connecting... connecting
optimized for large directories (up to ~1000 active rooms)
scanning network...
your room will appear in the public room list
ask the room creator for the room code
blckbx
p2p encrypted
e2ee
secure p2p with aes-256-gcm encryption
voice channel
connection
active users
voice channel
encrypted file transfer

library

choose theme

default (dark)
midnight blue
light mode
dark red
orange sunset
purple dream
100%
135°
135°
35%
saved themes include current colors, gradients, logo settings, and ui prefs.

settings

no settings match your search

presets hub

quick start styles for the full app. you can still tweak every setting after applying one.
theme-matched frame presets
glass presets
quick ui presets
chat bubble presets

profile

how you appear to peers in the current room.
images are downscaled + re-encoded as png for safety
updates your name for everyone already connected

chat behavior

controls message metadata and bubble display density.
chat bubble layout

notifications

set how the app notifies you about new activity.

appearance

adjust panel glass and frame visibility for readability.
72%

performance

recommended for mobile or low-end devices
removes backdrop-filter blur from all panels, modals and overlays — significantly improves scroll and animation performance on mobile

global gradients

base gradients used across app + panels when enabled.
22s
135°
135°

independent frame gradients

tip: keep global gradients on, then override specific frames here.
left frame
145°
20s
top frame
140°
22s
middle frame
145°
22s
right frame
225°
24s

screen share

security & privacy notice

IP address exposure

Your real IP address will be visible to all peers, even when using a VPN. This is inherent to WebRTC P2P.

browser extensions

Malicious extensions can access all content including encryption keys. Use trusted extensions only.

no forward secrecy

If your device is compromised later, recorded messages could be decrypted. Avoid highly sensitive topics.

identity verification

Use the fingerprint button to verify peer identities. Compare out-of-band to prevent MITM attacks.

file sharing risks

Always scan downloads for malware. Files are not scanned. Only download from trusted sources.

verify identity

Compare these fingerprints with your peer over a secure channel (phone, in person) to verify identity.

Your Fingerprint

Peer's Fingerprint

[ok] if fingerprints match: connection is secure
[!] if fingerprints don't match: possible mitm attack

how to use blckbx secure

01
security first
all messages, files, and voice are encrypted end-to-end with aes-256-gcm encryption and ecdh p-521 key exchange. no data is stored on servers. connections are peer-to-peer only.
02
choose room type
select private room for direct peer-to-peer connections or public room to browse, create, or join named rooms with multiple users. public rooms appear in the discovery browser.
03
discover & join
rooms are discovered through a gossip network - when you join a room, you learn about other active rooms from connected peers. the more rooms you join, the more you'll discover. alternatively, share room names directly for instant joining. all connections are end-to-end encrypted.
04
voice channels
join the voice channel to talk with all connected users. new users automatically connect when they join. voice is encrypted and peer-to-peer with no server relay.
05
file sharing (5gb limit)
share files up to 5gb with accept/reject prompts. when someone sends a file, you see the name, size, and type before accepting. files are encrypted, chunked, and sent p2p. executable files blocked. always scan downloads for malware.
06
safety features
built-in protection: rate limiting prevents spam, urls are validated and sanitized, malicious content is blocked, connections auto-recover from disruptions, and message history is never stored.