Palimpsest

Palimpsest is an encrypted diary and notes app with deniable vaults : one password field, any number of vaults, and no way to tell from the file how many there are. Every password opens its own vault. A decoy password shows a believable diary; another shows the real one.

Experimental, not audited. It protects against a curious partner, a thief and a quick border check. It does not protect against a forensic lab, spyware on the phone, or someone who keeps demanding passwords. If an adversary keeps copies of the file from different moments and knows a decoy password, a hidden vault can give itself away. The threat model in the source repository has the details.

Writing

Notes in a grid with folders, tags, pins and colours; a diary with a timeline and a month calendar; to-dos

Markdown editor that hides the markers away from the line you edit

Photos and voice notes captured in memory, never in the gallery; photos cropped before they are stored, EXIF and location dropped

Links between entries, backlinks and a graph of links where you link entries by dragging one onto another

Search, search inside an entry, trash with 30-day expiry

Vaults

Create, change the password, delete a vault (its blocks are overwritten in place)

A one-shot rule: on the next opening of this vault, destroy the vault with password X

Backup of everything, restore, export of one vault under its own password, import with merging

Privacy

No internet permission, no trackers, no ads

Screenshots blocked unless you allow them; no preview in recent apps

Incognito keyboard, no autofill, copied text cleared after 60 seconds

Locks on screen off, after idle time and in the background

The core is written in Rust: Argon2id, XChaCha20-Poly1305 and BLAKE2b; the container is a pile of 4096-byte blocks that all look like random bytes, with random chaff added all the time.