# Sigilock: Check your passwords without exposing them

> Local entropy + reuse analysis plus the HIBP k-anonymity pattern: SHA-1 split into prefix/suffix, the suffix matched on-device. 19 tested assertions.

Sigilock checks how strong your passwords are and whether they have been breached, without ever sending them anywhere. It combines local entropy and reuse analysis with the HIBP k-anonymity pattern: the SHA-1 hash is split into prefix and suffix, only the prefix is queried, and the suffix is matched on-device. It is a from-scratch, dependency-light build covered by 19 tested assertions that you can download and run locally.

## About the app

Secure-by-design thinking - applied k-anonymity

## What to take away

- Local entropy + reuse analysis plus the HIBP k-anonymity pattern: SHA-1 split into prefix/suffix, the suffix matched on-device. 19 tested assertions.
- Download: Sigilock (ZIP)

## Tags

Free software, Sigilock

## Read the full write-up

/downloads/sigilock.zip

## We build this for clients

https://dfieldsolutions.com/en/services/full-stack

## More from the lab

- https://dfieldsolutions.com/en/lab/sylex.md — Sylex: Make sense of the slashes
- https://dfieldsolutions.com/en/lab/kindra.md — Kindra: Miss a beat, not the rhythm
- https://dfieldsolutions.com/en/lab/voxara.md — Voxara: Argue better. Lose gracefully
- https://dfieldsolutions.com/en/lab/wraithward.md — Wraithward: Spot the bait before you bite

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Source: https://dfieldsolutions.com/en/lab/sigilock
DField Solutions — Torony köz 5-1.a, 2120 Dunakeszi, Hungary — +36 20 722 0002 — dezso@dfieldsolutions.com
Booking: see https://dfieldsolutions.com/en/contact