Encryption
How PinkyBond encrypts messages and calls
Everything she shares with you is encrypted on her phone and decrypted on yours. Our server forwards sealed envelopes it cannot open. We never hold the key.
Built on platform cryptography
We did not write our own crypto. On iPhone we use Apple's CryptoKit. On Android we use Google's Tink. Curve25519 key agreement, HKDF-SHA256 and AES-256-GCM on both, pinned to each other by shared test vectors, so an iPhone and an Android phone produce byte-for-byte identical ciphertext.
Key agreement
Curve25519 (X25519) ECDH
Encryption
AES-256-GCM
Key derivation
HKDF-SHA256
What we do, and what we don't
Every row is checkable. The last three are where we fall short of the best messengers, and we would rather you read that here than find it out later.
| Dimension | PinkyBond |
|---|---|
| Encryption | AES-256-GCM, end-to-end between the two phones |
| Key agreement | Curve25519 (X25519) ECDH, then HKDF-SHA256 |
| Implementation | Apple CryptoKit on iPhone, Google Tink on Android — byte-for-byte interoperable |
| Key storage | iOS Keychain / Android Keystore, hardware-backed where available |
| Pairing | QR code in person, or a 6-character code / link exchanged remotely; both public keys exchanged |
| Verification | A 6-digit code on both phones confirms no one sat in the middle |
| Account | None — no phone number, no email, no password |
| Ufikiaji wa seva kwa maudhui ya ujumbe na simu | Hakuna. Hatuhifadhi funguo kamwe. |
| What the relay stores | Kitambulisho cha kuunganishwa, aina ya ujumbe, muhuri wa muda, ukubwa, maandishi yaliyosimbwa — hufutwa mara tu yanapofikishwa, siku 30 zaidi |
| Picha, video na faili | Hadi 2 GB, zimefungwa kwa funguo mpya kwa kila faili ambayo ni simu zenu mbili pekee zinazo; hufutwa mara tu zinaposhushwa, siku 30 zaidi. Kwa programu ya mpenzi ambayo bado haijasasishwa: hadi 25 MB chini ya funguo ya kuunganishwa, huhifadhiwa siku 30 |
| Rekodi ya simu | Simu ipi iliyopiga, lini, simu ya sauti au video, matokeo na muda — inasomeka kwa seva yetu, huhifadhiwa siku 90, hufutwa mnapotenganisha muunganisho. Kamwe sauti au picha. |
| Push notifications | Carry no text; the phone decrypts locally |
| Safety Mode | Yes — her phone sends neutral substitute data instead of her real status. Your app shows no indicator, though the flag itself is in the snapshot. |
| Forward secrecy | No — one key per pairing |
| Open source | No |
| Independent audit | Not yet |
How pairing works
No phone number. No email. No account. In the same room, she shows a QR code and you scan it. Apart, she sends you a 6-character code or a link. Either way both phones exchange public keys, derive the same secret, and show a 6-digit verification code so the two of you can confirm no one sat in the middle.
She taps “Pair with partner” in PinkyBloom
Her phone generates a Curve25519 key pair (Apple CryptoKit on iPhone, Google Tink on Android)
She shows a QR code, or sends you a 6-character code or link if you are apart
You scan or enter it in PinkyBond, and your phone generates its own key pair
Your public key travels back to her the same way; both phones now hold both public keys
Each phone runs ECDH and HKDF-SHA256 to derive the same shared secret — nothing secret crosses the network
The shared secret is stored in the iOS Keychain or the Android Keystore
A 6-digit verification code appears on both phones; if they match, no one sat in the middle
The Blind Relay
Seva yetu ni sanduku la barua kwa bahasha zilizofungwa. Huhifadhi maandishi yaliyosimbwa mpaka tu simu nyingine iyapate, kisha huyafuta — siku 30 zaidi, ikiwa simu hiyo inabaki bila mtandao. Haihifadhi funguo kamwe. Arifa za push hazina maandishi; simu husimbua ndani yake.
PinkyBloom
Encrypts on her phone
Blind Relay
Huhifadhi maandishi yaliyosimbwa mpaka yafikishwe, siku 30 zaidi
Cannot decrypt
PinkyBond
Decrypts on your phone
Kila kitu seva yetu inahifadhi kuhusu ujumbe, faili na simu:
pairingId
Identifier for the pairing; not a name, number or email
senderRole
Which app sent it: PinkyBloom or PinkyBond
messageType
Aina gani ya bahasha ni — kwa mfano ujumbe wa mazungumzo, picha ya hali, risiti, au uanzishaji wa simu — kamwe kilicho ndani
timestamp
When it was sent
ciphertext
AES-256-GCM blob we cannot open; its length is the only thing we can measure
retention
Hufutwa mara tu simu nyingine inapoipokea; siku 30 zaidi ikiwa inabaki bila mtandao
relayReceipts
Baada ya kufikishwa, rekodi isiyo na maudhui: ni ujumbe upi na kama ulifikishwa au muda wake uliisha. Huhifadhiwa siku 30, ili simu ya mtumaji ionyeshe "haijafikishwa"
mediaObjects
Picha, ujumbe wa sauti, video na faili hadi 2 GB, zimehifadhiwa kwenye Cloudflare R2 kama maandishi yaliyosimbwa chini ya funguo mpya kwa kila faili ambayo husafiri tu ndani ya ujumbe uliosimbwa. Hufutwa mara tu simu ya mpenzi wako inapoipakua; siku 30 zaidi
callLog
Ni simu ipi kati ya mbili iliyopiga, lini, simu ya sauti au video, ilijibiwa, ilikosekana au ilikataliwa, na ilidumu muda gani. Inasomeka kwa seva yetu — hivyo ndivyo simu iliyokuwa imezimwa inavyojua kuhusu simu iliyokosekana. Huhifadhiwa siku 90, hufutwa mnapotenganisha muunganisho. Kamwe sauti au picha
Calls
Voice and video are peer-to-peer WebRTC with DTLS-SRTP and fresh keys for every call. The call setup rides the encrypted relay like any message. Before media flows, your phone checks the peer's DTLS fingerprint against a key derived from the pairing secret; a failed check aborts the call.
Wakati mtandao unapozuia njia ya moja kwa moja, Relay husambaza pakiti ambazo haiwezi kusoma. Hakuna seva ya midia inayosikia simu wakati wowote, na hakuna simu inayorekodiwa. Inafanya kazi kati ya iPhone na Android. Kinachohifadhiwa na seva yetu ni rekodi ya simu — simu ipi iliyopiga, lini, simu ya sauti au video, matokeo na ilidumu muda gani — kwa siku 90, ili mpenzi ambaye simu yake ilikuwa imezimwa bado aone simu iliyokosekana. Zaidi kwenye /calls.
Safety Mode
Encryption protects her data from outsiders and from us. Safety Mode is for the case where the person on the other end is the concern. She can pause sharing at any time, and he is never notified. She can also turn on Safety Mode, which substitutes neutral data he cannot distinguish from a real update.
When Safety Mode is active, the partner sees:
Phase
“Follicular”
Mood
“Good”
Energy
3 (Moderate)
The neutral data is encrypted and sent through the normal relay, so it looks the same as a real update in transit and on his screen.
Questions
Encrypted between the two phones. We never hold the key.
No phone number, no email, no account. The same cryptography on iPhone and Android, and a relay that forwards ciphertext it cannot open.
