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PRE-LAUNCH · WAITLIST OPEN

You own your data.

Encrypted on your device. Messages, documents, files — the surfaces our encryption boundary covers. The keys live with you; we never see them. The same wording the app shows on first launch, because the property is the product.

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nacl.box / 1:1 Sender-Key / groups WebAuthn / web Shamir / recovery
koaich · vault://board
YouTTL 24h
Q3 board memo attached. Per-recipient wrapping.
Naomi (counsel)TTL 24h
Got it. Reading now. [encrypted.file · 18.2 kb]
server.view
env(0x4a7c…d9 → 0x18b3…22) · 14:02:31 · 2,408 bytes
Server sees ciphertext.Only Naomi's device can decrypt this thread.
/ THE ASYMMETRY

Privacy as a property of the data, not a vendor promise.

01
ENCRYPTION BOUNDARY

Locked before it leaves your device.

Messages, documents, and files are encrypted on-device under keys your phone or laptop generated. The private key never reaches our server.

02
KEY CUSTODY

We hold ciphertext. You hold keys.

Our database stores scrambled bytes and operational metadata. There is no master key in a vault in our office. Nothing for an insider, a breach, or an external request to decrypt.

03
ARCHITECTURE

One trust model. Across everything you do.

End-to-end encryption applied not just to messages but to documents, files, group rooms, and email-bridged recipients — for work threads, family logistics, medical records, financial planning, anything that should stay yours.

/ CRYPTOGRAPHIC FOUNDATIONS

The same foundations that secure Bitcoin.
Applied to your conversations.

We use the same cryptographic foundations that secure Bitcoin — elliptic-curve keys, SHA-256, 24-word seed phrases — but applied to messaging with forward secrecy, sealed-sender metadata protection, and Argon2id key stretchingthat's an order of magnitude harder to brute-force than what Bitcoin wallets use.

SHOW THE PRIMITIVES →
X25519 + Ed25519
Elliptic-curve keys generated on your device
BIP-39 mnemonic
24-word seed phrase, the Bitcoin self-custody standard
Double Ratchet (1:1) + Sender-Key groups
Per-message forward secrecy on 1:1; group key rotates on member removal (MLS cutover for groups is roadmap)
Argon2id (19 MB / t=2)
Memory-hard KDF; ~5 orders of magnitude over PBKDF2-2048
/ COMPARE

The trust model, side by side.

Encryption claims sound similar. The trust model is where workspace tools split apart.

Koaich
SlackNotionGoogle WorkspaceMicrosoft TeamsDiscordSignalSMSFacebook MessengerLinkedIn messagesWhatsApp
E2E encrypted messages by default YesNon/aNoOnly 1:1 calls (opt-in)No (DAVE for voice only)YesNoYes (since late 2024)NoYes (Signal Protocol)
E2E encrypted documents Yesn/aNoCSE on Enterprise Plus onlyCustomer Key on E5 onlyn/an/an/an/an/an/a
E2E encrypted files YesNoNoCSE on Enterprise Plus onlyCustomer Key on E5 onlyNoYes (attachments in chats)n/aYes (in E2E chats)NoYes (attachments in E2E chats)
Can the vendor read your content? NoYesYesYes (default tiers)Yes (default tiers)YesNoYes (carrier reads all)No (content); Yes (metadata)YesNo (content); Yes (metadata)
Send to a non-platform recipient via email (encrypted) Yes (encrypted digest)NoShared link (cleartext)Yes (cleartext)NoNoNon/an/an/an/a
Group key rotation on member churn Yes (Sender-Key rotation)NoNoNoNoNoYesn/aYes (Signal Protocol groups)n/aYes (Signal Protocol)
Message TTL / auto-expiration Yes, every messageWorkspace retention policiesNoRetention policiesRetention policiesPremium, channel-levelYesNoDisappearing messages (opt-in per chat)NoDisappearing messages (opt-in per chat)
Per-vault key isolation YesNo (workspace-wide)NoNoNoNon/an/aNo (account-wide keys)n/aNo (account-wide keys)
Recovery without vendor-held keys Yes (Shamir + WebAuthn)No (password reset by vendor)NoNoNo (AD reset)NoYes (PIN)n/aEncrypted backups (opt-in PIN)No (password reset)Encrypted backups (opt-in PIN)
Operator business model Subscription (no ad-targeting)Non-profit (no ads)Carrier subscriptionAdvertising (Meta)Advertising + premium (Microsoft)Advertising (Meta)
Account identity tied to broader profile No (Koaich account only)No (phone or username)Phone number (carrier-bound)Yes (Facebook profile)Yes (LinkedIn profile + Microsoft)Yes (phone number, Meta-linked)
Cloud backup encrypted end-to-end Yes (by design)Yes (Signal-managed)n/a (carrier-stored)Opt-in (PIN required)Opt-in (PIN required, since 2021)
Contact list visible to vendor No (encrypted client-side)No (kept on device)Yes (carrier address book sync varies)Yes (Facebook contacts + uploaded)Yes (entire network is the address book)Yes (full phone-book upload by default)
Contact lookup uses keyed HMAC (vs. cleartext email) Yes (email_hmac)Yes (private contact discovery via SGX)n/aNo (cleartext)No (cleartext)No (cleartext phone numbers uploaded)
Sealed-sender (vendor can't see who sent the message) No (roadmap — see PRD)YesNo (carrier sees everything)NoNoNo
Post-quantum hybrid key agreement (1:1) Yes (hybrid)n/an/an/an/an/aYes (PQXDH)NoNot announcedNoNot announced

CSE = Google's Customer-Side Encryption (Enterprise Plus only). Customer Key= Microsoft's E5 customer-managed keys.

DETAILED COMPARISONS →
/ QUESTIONS

Worth answering.

Can you read my data?+
No. Your data is encrypted on your device with keys we never see. Our servers hold ciphertext and operational metadata only.
What if I lose my phone?+
Your other Koaich devices each hold a Shamir-split share of the recovery secret. As long as you have at least one other device, you can recover. We deliberately don't hold a vendor-side spare — if we did, an insider could too.
Does it work for people who aren't on Koaich?+
Yes. They get a daily digest email with metadata only. When they click 'Open in Koaich,' they sign up or enter a one-time code, and the body is re-encrypted client-side under their real key.
When does it launch?+
Active build now, on iOS and web. Invites open in waves to waitlist members.

MORE · /SECURITY · /COMPARE · /LEARN

/ GET KOAICH

Run your life. Privately.

Visit app.koaich.com. Add to your home screen. Done — no app store, no middleman.

Get Koaich →
Not ready yet? Get launch updates by email →
  • Get the early notification — claim your unique @handle before the public launch.
  • Skip the line — every colleague who joins via your referral link bumps you 100 spots closer.

Pre-launch · No spam · Unsubscribe anytime