-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 On 2016-06-21 06:10, Franz wrote: > On Mon, Jun 20, 2016 at 10:32 PM, Andrew David Wong > <a...@qubes-os.org> wrote: > > On 2016-06-20 18:05, Franz wrote: >>>> On Mon, Jun 20, 2016 at 1:51 PM, Andrew David Wong >>>> <a...@qubes-os.org> wrote: >>>> >>>> On 2016-06-19 08:40, Franz wrote: >>>>>>> On Sun, Jun 19, 2016 at 11:40 AM, Andrew David Wong >>>>>>> <a...@qubes-os.org> wrote: >>>>>>> >>>>>>> On 2016-06-19 04:38, Alistair Hutten wrote: >>>>>>>>>> Good evening, Alistair here from Australia, >>>>>>>>>> >>>>>>>>>> I'm after some help / recommendation to follow >>>>>>>>>> best practices (isolation between my different >>>>>>>>>> domains) >>>>>>>>>> >>>>>>>>>> My Current practice; >>>>>>>>>> >>>>>>>>>> - have encrypted vaults (cryptomator >>>>>>>>>> <https://cryptomator.org/>) one for personal, and >>>>>>>>>> one for work/business, - underlying encrypted >>>>>>>>>> files stored within Dropbox >>>>>>>>>> >>>>>>>>>> I do it this was because data is encrypted at >>>>>>>>>> rest, and more importantly before dropbox sees >>>>>>>>>> them, >>>>>>> >>>>>>> Careful: >>>>>>> >>>>>>> * Certain kinds of encryption are easier to break if >>>>>>> the attacker has repeated access to a changing >>>>>>> ciphertext. >>>>>>> >>>>>>> >>>>>>>> Also, who knows what the future bring and when. >>>>>>>> Quantic computing promises to be able to crack >>>>>>>> current encryption systems. When this happens and if >>>>>>>> you are aware of it, you would need to change all >>>>>>>> your passwords. >>>>>>> >>>> >>>> That mainly applies to asymmetric, not symmetric, >>>> encryption: >>>> >>>> http://pqcrypto.org/ >>>> >>>> >>>>> Thanks Andrew, I had a look only at the first paper of you >>>>> link and it tells that the quantum computer problem is >>>>> limited to public key encryption. While there is no problem >>>>> for secret key encryption which would be the case for vault >>>>> encryption. >>>> > > Well, it's not that quantum computing presents no problem *at all* > for secret key/symmetric encryption. Symmetric ciphers are still > thought to be vulnerable to Grover's algorithm, which basically > means that key length would effectively be halved (e.g., the > strength of AES-256 would be effectively halved to that of > AES-128), but this is obviously much less of a problem than the > crypto being completely broken (as would be the case for RSA, for > example). > >>>> >>>>>>>> I would not send my encrypted vault over the internet >>>>>>>> and would not open it with anything different from my >>>>>>>> vaultVM. >>>>>>> >>>> >>>> Data confidentiality is encryption's raison d'être. If you >>>> can't send the ciphertext over the internet, then what's the >>>> point of encrypting it? >>>> >>>> >>>>> Well my idea was that there is no 100% security guarantee >>>>> and it is only a matter of relative security. So I >>>>> considered that keeping my backups in a NAS over a personal >>>>> LAN was safer that sending them over the internet. >>>> > > That's fair. I think that might qualify as security through > obscurity (or maybe "security through non-availibility"), but > that's not to say it doesn't still provide some real degree of > security. > >>>>> But you link explains that I am wrong and that for any >>>>> reasonable future secret key encryption is 100% safe. So >>>>> thanks Andrew. This confidence certainly gives more peace >>>>> of mind. > > Well... I didn't mean to give that impression. IANAC (I am not a > cryptographer), but when it comes to encryption, I don't think we > should say that anything is "100% safe." It's not that the > algorithms are apodictically unbreakable. Rather, we derive our > confidence in them from the fact that lots of smart people have > spent lots of time trying to break them, and no one has been > successful yet (that we know of!). That's why there are > competitions to select algorithms. > > Also, even if the algorithm is secure, any given implementation > you use might not be. So, even though it's true (as people often > say) that the crypto itself is usually not the weak point in a > digital system, I also don't think (and didn't mean to give you the > impression) that it's "100% safe." > > >> You are right of course, but I was referring to sending encrypted >> vault over internet. It is not compulsory to do that. You can >> certainly live comfortably without doing that. So why should one >> do that? Only because there is expectation of a reasonable total >> safety, so that the difference to 100% may be negligible. >
I see what you mean. I think it still depends on your backup situation, though. If your only means of having offsite backups is to send (encrypted) backups over the internet (i.e., you can't physically move disks to another location or have someone else do it for you), then it may not be entirely true that you can "live comfortably without doing that." (I would live uncomfortably knowing that a fire could burn down my house and my backups along with it, since in that scenario I wouldn't have any offsite backups.) In other words, data availability counts for something, and I'm willing balance confidentiality against availability. (In a sense, this is obviously true. If I cared only about confidentiality and not at all about availability, I would just destroy all copies of my data immediately.) - -- Andrew David Wong (Axon) Community Manager, Qubes OS https://www.qubes-os.org -----BEGIN PGP SIGNATURE----- iQIcBAEBCgAGBQJXafrbAAoJENtN07w5UDAwUJMP/RsrE8f3m8kRA9JIfp6iHmQ+ N+ENmaPCaGd3UNbCusBokyEm5WKKMHAHcZUm6k5xDVlgKZiq9uxLJSJYFHNffW0L mVAWLvK/9lY2W3jsrZb2QZyYVKlENrHV+wuWbSJ6+0jyTPPFp4F+Qd9KhnayL+CD wbVoFrqHyO2zlFm4ZNKSuq/QNK0zDcdf3Jj2T7AxyvskMcz/6ycI0O0T4/HTyGOw sE15Jdf1ta34ze3iS2tNU7ExlsNfRNZvqn52Wj1VjGRgqnZxEsDUzv2pTTxc7ra/ YxSispQ8Cskjfh88nB8O9GVShT7LKk8PTy0PR3QV0713+1/iOjvgn1XpAclxO53e A+IuYAoB6YZOq4/RURa94ZsAyhm6YqAzOmapz+uKZzga3D/ytRNzd5MBJ8q1wDSG 4+GZtYFplz9xOomZvQDZp7MbkUjEvAvzkQqxC3BZBgiSnyIswLkwni0R2EAQc/oK lyxpQkLA1RpLhhaOs7ykmfqf5zAb9YbbgNs3KR7DAVFkP45Uu/cp3DmNMvVSfhYx ZxivK+b2sccCZXSDwFIMDRUCUB50xlYPrcKgMDFDE4v6doON4R4fJVXo9PAzqP7Q FqyqsbGtXo0nPEX0qYdNwxvSIBBXgJS2uhdW6Sr6jmeTDpekpCvVJ0bR1w+/FgQD meZSHfxadjK+vt2XqOts =OW4k -----END PGP SIGNATURE----- -- You received this message because you are subscribed to the Google Groups "qubes-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to qubes-users+unsubscr...@googlegroups.com. To post to this group, send email to qubes-users@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/qubes-users/f7d63a35-1b8a-3908-9670-e08566fe7a06%40qubes-os.org. For more options, visit https://groups.google.com/d/optout.
