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 |
| Akses server ke konten pesan dan panggilan | Tidak ada. Kami tidak pernah memegang kuncinya. |
| What the relay stores | ID pairing, jenis pesan, stempel waktu, ukuran, teks terenkripsi — dihapus setelah terkirim, maksimal 30 hari |
| Foto, video, dan file | Hingga 2 GB, disegel dengan kunci baru per file yang hanya dimiliki kedua ponsel Anda; dihapus setelah diunduh, maksimal 30 hari. Untuk aplikasi pasangan yang belum diperbarui: hingga 25 MB di bawah kunci pairing, disimpan 30 hari |
| Riwayat panggilan | Ponsel mana yang menelepon, kapan, suara atau video, hasilnya, dan durasinya — dapat dibaca oleh server kami, disimpan 90 hari, dihapus saat Anda batalkan pairing. Tidak pernah audio atau videonya. |
| 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
Server kami adalah kotak surat untuk amplop tersegel. Server hanya menyimpan teks terenkripsi sampai ponsel lain mengambilnya, lalu menghapusnya — maksimal setelah 30 hari, jika ponsel itu tetap offline. Server tidak pernah memegang kunci. Notifikasi push tidak membawa teks; ponsel mendekripsi secara lokal.
PinkyBloom
Encrypts on her phone
Blind Relay
Menyimpan teks terenkripsi hingga terkirim, maksimal 30 hari
Cannot decrypt
PinkyBond
Decrypts on your phone
Semua yang disimpan server kami tentang sebuah pesan, file, dan panggilan:
pairingId
Identifier for the pairing; not a name, number or email
senderRole
Which app sent it: PinkyBloom or PinkyBond
messageType
Jenis amplopnya — misalnya pesan chat, snapshot status, tanda terima, atau pengaturan panggilan — tidak pernah apa isinya
timestamp
When it was sent
ciphertext
AES-256-GCM blob we cannot open; its length is the only thing we can measure
retention
Dihapus segera setelah ponsel lain menerimanya; maksimal 30 hari jika tetap offline
relayReceipts
Setelah terkirim, catatan tanpa konten: pesan mana itu dan apakah terkirim atau kedaluwarsa. Disimpan 30 hari, agar ponsel pengirim bisa menampilkan “tidak terkirim”
mediaObjects
Foto, pesan suara, video, dan file hingga 2 GB, disimpan di Cloudflare R2 sebagai teks terenkripsi dengan kunci baru per file yang hanya berjalan di dalam pesan terenkripsi. Dihapus setelah ponsel pasangan Anda mengunduhnya; maksimal 30 hari
callLog
Ponsel mana dari keduanya yang menelepon, kapan, suara atau video, dijawab, tidak terjawab, atau ditolak, dan berapa lama berlangsung. Dapat dibaca oleh server kami — begitulah cara ponsel yang mati tetap tahu ada panggilan tak terjawab. Disimpan 90 hari, dihapus saat Anda batalkan pairing. Tidak pernah audio atau video
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.
Saat jaringan memblokir jalur langsung, relai meneruskan paket yang tidak bisa dibacanya. Tidak ada server media yang pernah mendengar panggilan, dan tidak ada panggilan yang direkam. Ini berfungsi antara iPhone dan Android. Yang disimpan server kami adalah riwayat panggilan — ponsel mana yang menelepon, kapan, suara atau video, hasilnya, dan berapa lama berlangsung — selama 90 hari, agar pasangan yang ponselnya mati tetap melihat panggilan tak terjawab. Selengkapnya di /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.
