ORWL – The first open source, physically secure computer
Having some physical security in a OSS-hacker-compliant form factor is really quite nice. This is not going to replace a proper HSM, and almost certainly is a less secure place to store your data than an iPhone; but it's a good start for those unwilling to give up on (the performance of) PCs.It's worth noting that QubesOS, which is supported by this system, protects against e.g. USB-based attacks by running a virtualized Linux for just the USB port (simplified.) This has its limitations, but should be pretty decent.If at all possible, try to ensure that this device is powered down when an attacker gets it. Several attacks are easier if that's not the case (e.g. USB-based attacks, but also cold boot attacks on the encrypted disk - the security monitoring should trigger when one opens the case, but if an attacker can still extract your disk password from RAM before the RAM fades you're in trouble...)