Encrypted before it is stored
File contents are encrypted on your device with AES-256-GCM before upload and decrypted on your device when you open them. The bytes on disk and the bytes in the cloud are the same ciphertext.
Anything with read access reads everything.
A coding agent you gave broad permissions, an MCP server, an npm postinstall script, an over-permissioned app, an infostealer: they all read the same plaintext your sync folder holds. Files you keep in SLIK are encrypted on your Mac before they are stored, so what sits on disk is ciphertext.
Download for Mac
macOS · Version 0.99.15 · DMG installer. iPhone app in development.
What a process with filesystem read access finds on disk
An ordinary sync folder
Plaintext at rest- ~/Dropbox/Taxes/2025-return.pdfopens: full return, SSN, bank details
- ~/Drive/Legal/passport-scan.jpgopens: readable image
- ~/Desktop/clients/acme-contract.docxopens: readable text
The same files in SLIK
Encrypted at rest- ~/Library/…/SLIK/objects/8f2c41e9…opens: AES-256-GCM ciphertext
- ~/Library/…/SLIK/objects/b07da33c…opens: AES-256-GCM ciphertext
- ~/Library/…/SLIK/objects/1ae95f60…opens: AES-256-GCM ciphertext
What that changes
Smaller blast radius
When something on your machine reads more than it should, the exposure is whatever was readable. Documents kept in SLIK are not readable that way without the unlock chain, so they are not part of what gets taken.
Your provider cannot read your files
We hold ciphertext, not documents. A breach of the storage provider, or of us, does not expose your file contents.
And what it does not change
- SLIK does not detect, scan for, block, quarantine, or remove malware, and it does not sandbox, block, or monitor AI agents. It changes what they can read, not what they can run.
- An attacker in control of your machine while SLIK is unlocked is a different threat model. At that point they can read what you can read.
- Local search runs on your device and its index can contain filenames and extracted text. That index is separate from the encrypted file contents.
- File-content encryption is distinct from account information and service metadata. Read the privacy policy.
How a file gets opened again
Four things stand between the ciphertext on disk and a readable file. All four live on your device.
Recovery phrase
A BIP39 phrase generated on your device. It is the root of your keys, and yours to keep.
Secure Enclave
Apple hardware on your Mac holds the key material that unwraps your keys locally.
Passcode
A four-character passcode you enter to unlock SLIK for a session.
AES-256-GCM
Contents are decrypted on the device as you open them, never on our servers.
Storage pricing
We are a small company and cannot subsidize large amounts of free storage. We charge for the space you use to pay for the storage and the work that goes into SLIK.
Free
Enough space to move a few files in and see how it works.
Download for Mac Free storage · No subscription$60 / year
$5/month equivalent, billed annually.
Download for Mac USD · Annual billing only$200 / year
About $16.67/month, billed annually.
Download for Mac USD · Annual billing onlyDownloading SLIK does not start a paid subscription. Paid plans are not sold on this website. Prices in USD; applicable taxes are shown before purchase.
Move the files you would not want read.
SLIK 0.99.15 for Mac. Download the DMG to get started.
Download for Mac