WINJAB
Security & privacy
What is protected, how, and — just as plainly — what is not.
| File contents | AES-256-GCM, one record per block | |
| File names, sizes, timestamps, attributes | the manifest is one AES-256-GCM record | |
| Per-block SHA-256 and CRC-32C | the chunk table is one AES-256-GCM record | |
| Archive size, block count, uncompressed total | the header stays readable, and there is no padding to hide it | |
| Who made the archive | there are no signatures: a valid tag proves someone had the password, nothing about who |
The whole scheme reduces to the password. PBKDF2 at 600,000 iterations costs an attacker roughly half a second per guess on one core — but a GPU does hundreds of thousands of guesses a second, and specialised hardware does more. A long passphrase is the only defence that scales.
A memory-hard function such as Argon2id would resist GPUs better. Windows CNG offers none, and this project implements no cryptography of its own, so PBKDF2 is what is used. It is named here rather than glossed over.
An archive that opens with your password was made by someone who had your password. Nothing in the format says who, and nothing proves an unprotected archive is unaltered.
No claim is made that a password cannot be recovered from the running process's memory.
Nothing here claims to erase data beyond recovery on an SSD. Wear levelling means a file's old blocks can survive an overwrite, and this program makes no promise it cannot keep.
Nothing. There is no network code in the archiver: no telemetry, no update check, no crash reporting, no account, no advertising identifier. The only addresses in the program are links you choose to click, and they open in your browser.
Privacy policySettings
A plain text file in your own AppData folder. You can read it, edit it or delete it; a value this build does not accept falls back to the default.
Recent archives
A list of paths and sizes, kept in the same folder, so the home screen can show what you worked on. Deleting the file clears it.
Your archives
Written where you asked and nowhere else. Extraction never writes outside the folder you chose.
Shell integration
Registry entries, added only when you press Install and removed when you press Remove.
If you find a security problem, write to [email protected] with enough detail to reproduce it. Please do not post it publicly until there is a fix to go with it.
The threat model, the container format and the measured benchmark are documents in the source repository rather than marketing copy: THREAT_MODEL.md, FORMAT_JAB_V1.md and PERFORMANCE_BENCHMARK.md.