Scantic
End-to-end encrypted sharing
How Scantic protects a scan you share · last updated 31 July 2026
Scantic computes your scans on your iPhone and keeps them there. Sharing is the one action that sends a scan anywhere, so it is the one place where encryption matters. We built it so that we cannot read what you share.
Private and password links are encrypted on your iPhone before anything is uploaded. The key that opens them travels inside the link itself, in a part of the address that browsers never send to servers. Our server stores data it cannot read.
The three ways to share
You choose per scan. The difference is not a setting buried in a menu. It is the first thing the share sheet asks.
Anyone with the link
The scan is sealed on your iPhone. Whoever opens the link can view it. Anyone who does not have it cannot, and that includes us.
Link and password
As above, and the password is folded into the key. Someone who intercepts the link still needs the password. The password itself is never uploaded.
Public
Deliberately not encrypted, so that messaging apps can show a real preview image. You pick this one knowingly; the app says so before you publish.
Why we cannot read your scan
A share link looks like this:
https://scantic.app/s/<id>#k=<key>
Everything after the # is called the fragment. Browsers treat it as a local instruction: it is never put into the request that goes to a server. It does not appear in our logs, at our hosting provider, or anywhere in between. The scan is decrypted in the recipient's browser, on their device.
That is the whole trick, and it is why this is not a promise about our good behaviour. We do not hold the key, so there is nothing for us to hand over, lose or be compelled to produce.
What we use
Standard, published cryptography from Apple's operating system. No algorithms of our own invention.
- AES-256-GCM seals the scan and its metadata, giving both secrecy and tamper detection.
- HKDF-SHA256 derives a separate key for each part, so one key cannot open the other.
- PBKDF2-HMAC-SHA256 with 600,000 iterations turns a password into a key, which makes guessing expensive.
- TLS protects the transfer itself, on top of the encryption that is already in place.
Technical description
The full write-up: key derivation, data format, pre-processing, key handling and the limits of each mode. Written for reviewers, auditors and the curious.
What we honestly cannot protect
Encryption is a tool with edges, and it is worth naming them.
- A link is a key. Anyone you send a private link to can forward it. Treat it like a house key, not like a name.
- Copies stay copies. You can switch a link off at any time in the app under My Shares, and the stored data is deleted at once. Whoever already downloaded the scan keeps what they have.
- Public links are readable. That is their purpose. If a scan should not be readable, do not publish it.
- We see that a share exists. The server knows a piece of encrypted data was stored, its size and when. It does not know what it is, whose it is, or what it shows.
No account, nothing attached
There is no sign-up, no email address, no device identifier and no analytics anywhere in Scantic. A share carries the scan and nothing about you. Your camera footage, your photos and your location never leave the iPhone at all.
More on what is stored and for how long: the privacy policy.