The DiskAshur M2 from iStorage (starts at $142 for 120GB, $275 for the 1TB version we tested) excels at the primary mission of any security-focused SSD: making sure that no unauthorized person can ever get their hands on your data. It succeeds thanks to hardware encryption, PIN authentication, and what is, in effect, a self-destruct mechanism should anyone breach its housing. This SSD repels the elements, too, impervious to water and dust, and it’s shockproof and crushproof. Like most security-centric external SSDs, the M2 isn’t particularly fast as SSDs go, and you do pay a premium for its protective features, but it’s not as dear as many similarly equipped SSDs we have reviewed. That fact and the feature set tip the scales in favor of the DiskAshur M2 as our latest Editors’ Choice winner for secure external SSDs.
Boxes Within Boxes
Unboxing the M2 proved an apt visual metaphor for the drive’s security—simply getting to the product was rather like opening a set of Russian nesting dolls.
It arrives in a 6.5-by-4.5-by-2-inch cardboard box, illustrated with pictures of the drive and its case and providing brief descriptions of key features. When you open the box, in addition to finding a quick-start guide and two cables, you will see a cardboard cradle that holds a hard-plastic carrying case—imprinted with the iStorage name—that contains the drive. The case has a looped strap for easy carrying, and it unzips to reveal a black slab, stamped with the product name, with a silver base.
This monolith is itself but a sleeve that protects the drive. When you pull the sleeve and (tightly fitting) base apart, the DiskAshur M2 reveals itself as a slightly smaller black rectangle, measuring 4.2 by 1.8 by 0.48 inches (HWD). An alphanumeric keypad—replete with three status lights—adorns its side. Like most external SSDs, you’ll never see the actual drive mechanism—in fact, if you were to break open the M2 to get to the chips and the PCB inside, it would be damaged beyond repair. It’s designed to be physically uncrackable.
The included quick-start guide instructs you on how to set an Admin PIN before first use, and how to unlock the drive with it. PINs must be between seven and 15 characters, and a Shift key lets you toggle between letters and numbers. You can also set individual User PINs, and if a user forgets their PIN, the drive can be unlocked using the Admin PIN. The administrator can then let the user set a new User PIN. The administrator can also set a self-destruct PIN that’s very much a “nuclear option.” Once that kill-PIN is entered, the data, the encryption key, and all PINs are deleted, rendered lost forever.
Both the administrator and the user can configure the DiskAshur M2 as a read-only (write-protected) drive. If configured by the admin, the drive cannot be modified or disabled by the user, allowing the admin to pre-provision a drive with pre-loaded content as read-only for the user.
Ruggedness and Encryption
Then there’s the physical proofing. An ingress protection (IP) rating of IP68 means that the M2 is highly resistant to water—indeed, most anything short of high-pressure cleaning or a steam jet. The drive can survive a dunking in 1.5 meters of water for 30 minutes, and it’s also impervious to dirt, sand, and dust.
This is the highest IP rating of any drive I have tested, and it matches that of the general-purpose ADATA SE800. But the M2 brings still more ruggedness to the table. It is shockproof—able to survive a drop of 4 meters onto a concrete surface—and crush-proof, able to withstand being run over by a 2.7-ton vehicle. (We’d have liked to have borrowed a pickup truck to test that last claim, but we will have to take iStorage’s word for it.)
The M2 is also compliant with FIPS 140-3 Level 3, a set of federal standards that describe security protocols for use by US government contractors and vendors. Meeting these standards requires that steps be taken to protect not just the data stored on the drive, but the hardware itself. This encompasses the tamper-proof case mentioned earlier. The M2’s internal components are encased in epoxy resin, and any attempt to pry inside to get to the chips will result in their destruction.
The M2 employs AES-XTS 256-bit hardware encryption, which is even more secure than the AES 256-bit hardware encryption that is often found on standard external SSDs. AES-XTS is particularly good for full-disk encryption.
A great thing about the M2 is that because its encryption is hardware-based, the drive is operating-system- and host-independent, so you can use it on most any system with a USB port, without having to install software. (Of the two USB cables included with the M2, one connects to a computer’s USB Type-C port, the other to a USB Type-A port.) According to iStorage, the drive is compatible with Windows, macOS, Linux, Chrome, Android, thin clients, zero clients, embedded systems, Citrix, and VMware. To lock the drive, you simply unplug it from the computer. (Just be sure that any data transfer in progress completes before doing so.)
Testing the DiskAshur M2: It’s Security Over Speed
We ran our usual suite of SSD tests on the M2, comprising Crystal DiskMark 6.0, PCMark 10 Storage, BlackMagic’s Disk Speed Test, and our own folder transfer test. The M2 is rated at 370MBps for both sequential read and write speeds. As we don’t have a huge pool of secure hard drives to compare it against, we broadened our selection based on some key criteria. Of the drives included for comparison, they have at least two out of three of the following features: strong (at least 256-bit AES) hardware encryption, some other notable security attribute (such as PIN authentication from an onboard keypad, or fingerprint authentication), and ruggedness features including an IP rating. (See more about how we test SSDs.)
Even within these categories, not all attributes are equal. For instance, the Samsung Portable SSD T7 Touch earned our Editors’ Choice award largely on the inclusion of a fingerprint reader that can be used instead of its password authentication, but while fingerprint authentication is the height of convenience, it is not particularly secure. While both the SanDisk Extreme Portable SSD V2 and SanDisk Extreme Pro Portable SSD V2 have some ruggedness cred, their ingress protection ratings of IP55 fall short of the DiskAshur M2’s IP68, and they are not as shock-proof, let alone crush-proof, as the M2.
Among the drives included in these charts, the ones most similar to the M2—which I think of as armored or lockbox drives—are the Apricorn Aegis Fortress L3, the DataLocker DL4 FE (currently under review), iStorage’s earlier DiskAshur Pro2, and the SecureData SecureDrive BT. Think of these as our core group of comparison drives.
The test results above are split into two tiers, with the top tier being the conventional SSDs and the lower scorers being the lockbox drives. Compared with the others in its group, the M2 did rather well, coming in first or second on each of the tests. It did fall short of its speed ratings of 370MBps for both read and write; in Crystal DiskMark 6.0 sequential read/write testing, it scored 333MBps for read and 321MBps for write. Still, these scores were faster than all of the other lockbox drives we tested except for the DiskAshur Pro2, which scored barely better at 339MBps for read and 332MBps for write.
Verdict: A Rare ‘Value’ Security SSD
The M2 bears a lot of similarities to the Apricorn Aegis Fortress L3, which we reviewed in February 2020. There are actually two Apricorn drives by this name, one a spinning hard drive, and the one we reviewed, which is SSD-based. Our main gripe with the Aegis L3 was its exorbitant price, about 70 cents per gigabyte. Although the L3 SSD has come down somewhat in price, it is still expensive, costing 50 cents per gig from Apricorn and 47 cents per gig through Amazon at this writing.
In contrast, the 1TB version of the M2 costs barely half of that (28 cents per gig, for example, through Amazon at our test capacity), has similar security features, and is rated as even more rugged than the L3. Plus, it served up higher Crystal DiskMark sequential-speed scores for both read and write. The DiskAshur M2 thereby earns its place as our latest Editors’ Choice winner for secure external SSDs.
