A pattern onlyyou can draw.

Why a pattern, and why 5×5

A pattern is quick to draw and easy to remember as a shape, which is why so many people already use one to unlock their phone. The classic 3×3 grid is its weakness: with only nine dots there aren’t many shapes to choose from, and the common ones are easy to guess or to spot on a smudged screen.

Sigilock uses a 5×5 grid. Twenty-five dots, with lines that can jump across the grid, make for vastly more possible sigils, and room for shapes that mean something only to you.

What happens when you draw

Your sigil is never saved. Each time you draw it, Sigilock turns the sequence of dots into key material, mixes it with a secret that lives in your phone’s Keychain or Keystore, and runs it through deliberately slow rounds of encryption calibrated to take about 0.7 seconds on your phone.

If the result unlocks a vault, it opens. If it doesn’t, the lock screen simply says no vault opens with this pattern, and the attempt goes into your intruder log. Because every attempt costs the same work, there is no shortcut for someone trying patterns one after another.

How the strength meter scores you

The meter uses the same rules as the lock screen. A sigil needs at least six dots and at least one turn; straight lines are rejected outright. Beyond that, every extra dot, every change of direction and every jump to a non-neighbouring dot adds to the score, from Fair through Strong to Excellent.