Palimpsest application pour Android description
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.
