Kofrix security, explained plainly
AES-256-GCM, PBKDF2, a recovery key that never stays on the phone, and the limits to know.
Separate keys for separate jobs
Your 5 × 5 pattern is stretched with PBKDF2-SHA512 (600,000 iterations) and a salt kept in the phone’s secure keychain. The result opens your vault’s master key, which in turn opens the vault index.
Authenticated encryption, file by file
Each file has its own random key and is encrypted in 1 MB blocks with AES-256-GCM. Every block is bound to its file and position, so a modified or reordered file is detected.
A recovery key that never stays on the phone
Your recovery phrase is stretched (PBKDF2, 800,000 iterations) into an X25519 key pair. The phone keeps only the public key; each new vault leaves its recovery envelope for that key. Opening an envelope requires the phrase itself.
A discreet entrance
There is no list of vaults. The unlock screen is identical with zero or ten vaults, and an unknown pattern opens a new empty vault. Photos are never written to disk unencrypted, apart from a temporary copy while a video plays, deleted right after.
Limits you should know
Kofrix hasn’t had an independent security audit yet. Files live only on your phone: there is no backup for now. A short or obvious pattern is easier to guess, and a phone with malware can see what is on screen.