[FEATURE REQUEST] - Iteration

[marioaltecci]

"Hello! Great app, I enjoy using it.
I kindly request that you add the ability to increase the number of PBKDF2 iterations above 500,000 (for example, to 1–2–4 million or at least to 1 million).
Why is this important?
OWASP 2025–2026 recommends a minimum of 600,000 iterations for PBKDF2-HMAC-SHA256, and 1 million+ for paranoid protection.
On modern flagships (Snapdragon 8 Gen 3/4, Dimensity 9300+, Tensor G4, etc.), even 1–2 million iterations provide an acceptable first vault opening time (3–8 seconds), and protection against brute-force/offline attacks increases significantly.
For users who store highly sensitive data (personal photos/videos, documents), this is critical — especially if the vault may be subject to forensic analysis (Cellebrite/Oxygen, etc.).
Currently, 500k is already good, but the option to increase it to 1M+ will make the app one of the most secure FOSS vaults on Android.

Thank you in advance, this will really increase the level of privacy for many! 🔒

[hej2010]

The problem with increasing it is that it will take, in your example, 3-8 seconds for every file to load/display, not just the first time you open the app as all files are encrypted individually with unique key data.

[marioaltecci]

The problem with increasing it is that it will take, in your example, 3-8 seconds for every file to load/display, not just the first time you open the app as all files are encrypted individually with unique key data.

Okay, thanks for clarifying!
I fully understand the problem — per-file encryption makes high iterations really painful for everyday use, especially when scrolling through a gallery.
500,000 is already an excellent compromise, and with a strong passphrase (6+ words), it provides very cool protection without slowdowns.
If you ever want to improve it (for example, optional master-key cache in memory during a session or "paranoid mode" for powerful devices), that would be awesome, but even now the app is top-notch.