Hi Mac'!
Big topic and part of my regular consulting!
Basically, following good computer hygiene at home translates to the same while on-tour. Here are some quick tips the average user can use to keep safe; I'll keep this entry short and sweet as a glossy thumbnail sketch...
• Regardless of your device, keep it up-to-date, especially on security updates. This is as important with phones as it is computers like desktops, laptops and tablets, regardless of operating system.
• You can purchase a subscription to a Virtual Private Network (VPN) and use it as often or long as you wish. A VPN adds security and privacy to both private and public networks, like WiFi Hotspots and the Internet you'll be most apt to use while touring. VPNs are most often used by corporations to protect sensitive data. There are a number of VPNs that work well at reasonable monthly rates. They vary in their speed and the locations you can set, so check first and make sure the VM is provided by a reputable firm, since all your traffic will go through it. One I use is TunnelBear, because the same price covers my Windows computers as well as my Android phones. They have a flavor for Apple products also. I pay USD$2.72/month for my subscription. A VPN primarily secures your communications and is a real boon when using public wifi. For more on the topic of VPNs, see this custom Google search:
https://www.google.com/search?q=whag+is+a+vpn%3F&oq=whag+is+a+vpn%3F&aqs=chrome..69i57j0l5.6282j0j9&sourceid=chrome&ie=UTF-8#q=what+is+a+vpn?Secondarily -- quite apart from security -- a VPN is also useful for planning trips in advance from home, as you can also virtualize your location and so view videos, news, and such that would otherwise be geo-restricted to their home markets. This is especially handy if you like to get a handle on news of events in other locations that may impact your tour when you arrive. I used my VPN for this when I was in Turkey and wanted to view local videos of the massive flooding in Serbia. The level of detail available in local Serbian news allowed me to better plan and time my arrival and via a different route. The route I had planned on was unusable. It also showed me just where the mines had been washed from their marked locations and so it was no surprise when I found them scattered across the road and chose to sleep in a farmer's brick-lined hay crib instead of wild camping in a field or forest.
Once my apparent location has been changed, Google tailors results by location and if the location of your device is determined by network rater than GPS, you'll get localized results. All links are local for the countries where my VM has nodes. Very handy for research and planning. TunnelBear is pretty typical of what's available in a VPN app, with virtual locations in the US, UK, Canada (where TB is located), Germany, Japan, Australia, France, Ital, Netherlands, Sweden, Switzerland, Ireland, Spain, Singapore, Norway, Denmark, Hong Kong, Brazil, Mexico, and India.
• I use a number of virtual machines in my consulting work. Most of my computers have really fast processors and lots of memory, so they work well running VMs which usually require both. VMWare and Oracle make good products, and there are others like VirtualBox, Parallels,and QEMU (if you like Linux as I do).
For Windows machines, there have been a number of "lightweight" virtual machines that stretch the definition of the term by creating "session sandboxes" so your browsing and other activity are wiped clean after each restart. They tend to come and go on the market and their availability and popularity wax and wane as money is available for the developers to update them for new OS versions. I've tried most over the years, but among them ones that worked well for me back in the day were Wondershare TimeFreeze, ToolWiz TimeFreeze, Faronics' Deep Freeze, Shadow Defender, Rollback RX. SandboxIE, Returnil. Most install themselves in Upper Filters and so can conflict with imaging programs (Acronis True Image is one such conflict...and some don't work well with SSD drives) so it can take awhile to get these "lite" VMs to play nicely with each other.
I sometimes use VMWare's Horizon Client on my Android phones to work on my VMware Horizon virtual desktops and hosted applications from afar, but that is "work" and not "security".
• Besides the usual malware, the biggest computer security problems I've run into while traveling are BlueJacking, AP spoofing, and hardware keyloggers I sometimes see plugged into the back of public-use desktop computers. To deal with these issues, I generally keep my Bluetooth radio turned off unless I need it paired for a specific purpose/client, like my wireless keyboard. For the AP spoofing, I check to make sure I am connected to the wireless network I intend and use my VPN, and for the keyloggers, I use software that basically allows me to cut-and-paste my passwords instead of typing them out. Any financial transactions are done over a(proven trustworthy) VPN.
Besides my smartphone, I also take a small flash drive on my wind jacket's zipper pull and load it with a standalone (portable) Linux OS and applications and if there is a way to physically access a public use computer (many are available in hotel lobbies and conference rooms and front offices and even in some European parks), I will ask if it is alright to boot into my drive. Each time I've asked, my request was approved. The overwhelming number of public machines I've encountered are Windows machines, so plan accordingly. An aside: Not all keyboards you'll find on public machines are the same, so be prepared to spend some time making typos until you adapt. I've encountered QWERTY, AZERTY, DVORAK, QWERTZ, and JCUKEN.
If you're looking for free software with lots of community reviews, I can heartily recommend Gizmo's Freeware, which I've followed since its start:
http://www.techsupportalert.com/ Once there, look under the "Security and Privacy" tab for your operating system. Contained in the reviews are good, clear instructions in setup and use. I think you'll like it, Mac'.
Also, you can do a Google search for "How to setup a virtual machine" by Operating System (OS) and go from there. Here's one such result:
https://www.storagecraft.com/blog/the-dead-simple-guide-to-installing-a-linux-virtual-machine-on-windows/Over time, I've moved solidly to Android smartphones for my on-tour computing, mostly because I could not meet the off-grid power demands of laptop computers; even my little netbook required more power than I could readily supply via dynohub or solar. Smartphones are also physically smaller than any laptop computer. Along these lines, you may wish to read up on US border policies if you are planning to travel here (I live near the upper-left corner of the US, in Oregon). The US border is not the same as the interior, and phones, laptops, and other devices can be seized and cloned by border officials and their contents dissected later. I don't like it, so I have my bookmarks and mail stored on Google with my Google credentials. Before crossing into the US, I erase my phone by resetting it to factory specs and signing out of my Google accounts. Once past security, I sign back in again and all is restored after a few minutes -- apps, browser history, mail, and passwords. My photos, music, and maps are all stored on separate micro-SD cards which I also remove and replace. You can read more here:
https://www.google.com/search?q=us+border+cloning+of+phones&oq=us+border+cloning+of+phones&aqs=chrome..69i57.6743j0j9&sourceid=chrome&ie=UTF-8Hopefully the above will give you some leads to pursue so you can assemble a security package best suited to your travel needs. I'd go into greater depth, but that would go beyond the scope of a bicycle-related forum.
All the best,
Dan.