CofferShield is a desktop application for Windows and Mac. It runs entirely on your own machine — there is no account, no subscription and no cloud. Please check this page before you buy, because the requirements are firm rather than advisory.
Windows
Windows 10 (May 2018 update) or newer
Mac
macOS 11 Big Sur or newer
CofferShield needs a window at least 360 pixels wide and 600 tall, so it works on a small laptop screen as well as a large monitor. It has a dark and a light appearance; you choose which.
| Device or system | Why not |
|---|---|
| Windows 7, 8 and 8.1 | Microsoft stopped supplying the display component CofferShield needs on these versions in January 2023, and stopped issuing security updates for the systems themselves years earlier. There is no way to install it, and we would not recommend keeping a vault of this kind on a computer that no longer receives security patches. |
| macOS 10.15 Catalina and earlier | The interface relies on layout features Safari only gained in macOS 11. On older versions the app would open but display incorrectly. |
| Windows on ARM | Not built natively yet. Recent ARM devices such as Surface can run it through Windows' built-in translation, but we do not test that configuration and cannot support it. |
| iPhone, iPad and Android | There is no mobile version. Your vault stays on your computer by design. |
| Web browsers and Chromebooks | CofferShield is not a website and there is nothing to log in to. It is an application you install. |
| Linux | Not released. If there is demand we will look at it. |
Available on both systems On Windows, you can choose to unlock CofferShield with Windows Hello — your fingerprint, your face, or your device PIN — instead of typing your master password every time.
On Mac, the same is available through Touch ID. macOS offers two ways to store the saved key and CofferShield asks for the stronger one first: the key sits behind an access control that requires biometry, and macOS refuses to hand it back without a successful Touch ID — a check enforced below the application rather than requested by it. If your machine cannot provide that mode, the key is stored the ordinary way and the security note in Settings tells you so, rather than claiming the stronger one.
Two things worth knowing on either system. Adding or removing a fingerprint on the machine invalidates the saved key, by design. And changing your master password clears the stored copy, because the data key itself does not change when the password does.
Quick unlock is off until you switch it on, and your master password always works regardless. Section 12 of the Security Architecture Whitepaper sets out both designs in full, including where the Windows one is weaker.
Everything else is the same on both systems: the encryption, your vault file, backups, the estate and incapacity records, printing, the auto-lock timer, the session PIN and the decoy vault.
If you want share and cryptocurrency prices to update themselves, that feature needs the internet and a free key from a price provider. It is switched off until you set it up, and CofferShield contacts nothing but those four providers. Leave it off and the app never opens a network connection at all.
CofferShield can print an emergency access sheet, an heir sheet for each person you name, and a wallet-sized card carrying your healthcare contacts. Any printer your computer already uses will do, and you can save any of them as a PDF instead of printing.
The wallet card is designed to be cut out to the size of a credit card. Printers vary, so check the first one against an actual card and adjust the scale in your print dialog if you need to.
Your vault is a single encrypted file on your own machine. You can back it up yourself to a USB stick or an external drive at any time — that backup is the only copy that exists, so please make one.
A backup made on Windows opens on a Mac, and the other way round. The file format is identical on both, so moving between computers or switching from a PC to a Mac is a matter of copying the backup across and opening it with the same master password.
CofferShield is from a small publisher, so your computer may not recognise it yet.
If either message makes you uncomfortable, please write to us before installing rather than clicking through it.
CofferShield does not update itself and does not check for updates, because that would mean contacting a server. When there is a new version we will tell you, and you install it the same way you installed this one. Your existing vault opens in the new version unchanged.
Please do not buy it. If you already have and your system turns out not to meet the requirements above, contact us and we will refund you — we would rather do that than have you fighting an installation that cannot work.