Question 1

Are PinkyBond calls end-to-end encrypted?

Accepted Answer

Yes. Audio and video travel peer-to-peer over WebRTC with DTLS-SRTP, so the media is encrypted between the two phones. The call setup (offer, answer, network candidates) rides the same end-to-end encrypted relay as your messages — AES-256-GCM under your pairing key. Each call derives its own key material, so a recording of one call cannot be unlocked with another call’s keys.

Question 2

Can PinkyBond, Apple or Google listen to a call?

Accepted Answer

No. There is no media server. When both phones can reach each other directly, nothing but the two of them touches the audio. When a network makes a direct path impossible, a relay (TURN) forwards the encrypted packets — it cannot decrypt them. The relay never sees the pairing key and never receives plaintext.

Question 3

How is this different from Signal or WhatsApp calls?

Accepted Answer

The encryption primitives are the same family, and Signal has the longer audit history, open source code and forward secrecy for messages — we say so in the table. The difference is who can reach you. Signal and WhatsApp identify you by phone number, and anyone who has it can call you. PinkyBond has no accounts and no numbers: the only person who can call you is the partner you paired with, by QR code in person or by a code exchanged remotely, and each call’s DTLS fingerprint is checked against a key derived from that pairing secret before media flows. A failed check aborts the call.

Question 4

Are calls free?

Accepted Answer

Yes. PinkyBond is free. Calls, chat and the forecast are all included.

Question 5

Does it work between iPhone and Android?

Accepted Answer

Yes — an iPhone and a Pixel call each other directly. On iPhone the call uses the native call screen (CallKit); on Android it is a first-class Telecom call, so it rings, shows on the lock screen and respects Do Not Disturb like any phone call.

Question 6

What does the server know about a call?

Accepted Answer

お二人のペアリングについて通話履歴を保持します: どちらの端末が発信したか、いつ、音声かビデオか、応答・不在着信・拒否のいずれか、そして通話時間。これによって、何日も電源が切れていたパートナーの端末でも不在着信を確認できます。履歴は90日間保存され、ペアリングを解除すると削除されます。名前も電話番号もメールアドレスもなく、ペアリングIDのもとに記録され、アプリの匿名の利用分析と結び付けられることは決してありません。サーバーが音声や映像そのものを受け取ることはなく、通話が録音されることもなく、相手の端末を鳴らすプッシュ通知に内容が含まれることもありません。

Dimension	Signal	WhatsApp	FaceTime	PinkyBond
Media encryption	SRTP (Signal Protocol keys)	SRTP	SRTP, keys per FaceTime session	DTLS-SRTP, per-call keys
Identity	Phone number	Phone number	Apple ID / phone	None — your pairing (QR in person, or a code exchanged remotely)
Who can call you	Anyone with your number	Anyone with your number	Anyone with your ID	Only your partner
MITM protection	Safety number (manual check)	Security code (manual)	Apple key directory	Fingerprint bound to the pairing secret, checked automatically
Server in the audio path	Relay when needed	Relay when needed	Relay when needed	TURN relay when needed; cannot decrypt
Audit history	Extensive, public	Partial	Apple internal	Platform crypto (CryptoKit / Tink); no independent audit yet
Open source	Yes	No	No	No
Forward secrecy	Yes	Yes	Yes	Calls: fresh keys per call. Messages: no — one key per pairing
Knows the relationship	No	No	No	Yes — same app as her forecast and your check-ins

A phone line only the two of you can pick up

Peer-to-peer first

Bound to the pairing

Per-call keys

No content in the ring

Honest comparison

Why a couples app needs its own phone line