tag:blogger.com,1999:blog-16750015.post6554341800567311269..comments2024-01-24T20:01:37.600-05:00Comments on slight paranoia: How Dropbox sacrifices user privacy for cost savingsChristopher Soghoianhttp://www.blogger.com/profile/08950937382104783909noreply@blogger.comBlogger99125tag:blogger.com,1999:blog-16750015.post-42926925177856528662015-02-24T06:11:31.420-05:002015-02-24T06:11:31.420-05:00A few recommendations:
1 - Do not rely on 3rd par...A few recommendations:<br /><br />1 - Do not rely on 3rd parties for your only backup - take a local copy. Dropbox could go into administration tomorrow - where is your data or their comforting words then?<br /><br />2 - If you use Dropbox for filesharing - e.g. on several devices, it is not a good backup. What I mean is it doesn't meet the true definition of a backup e.g. a secure copy of important data. What happens if your PC has disk corruption on your dropbox folder during a disk check when it boots up? The corruption is duplicated to the server and all your devices when dropbox starts. A backup should ideally be be separate from normal day-to-day data.<br /><br />3 - Do not trust seriously private data to any 3rd party. Encrypt it locally with the strongest encryption you can, and if it is that private, save it to an external disk and put it in a safe.<br /><br />The old methods still work. <br /><br />An old adage in privacy and security is "Trust No-one".Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-16750015.post-32417718462199164462014-03-25T16:44:31.920-04:002014-03-25T16:44:31.920-04:00So with the way deduplication works, is it simply ...So with the way deduplication works, is it simply deleting the duplicate copies of a particular file? Or is it keeping, say a fifth copy, of that file uploaded in a user's Dropbox account, but decrypting that file and assigning the encryption key to another user?Yvettenoreply@blogger.comtag:blogger.com,1999:blog-16750015.post-33949463654359791502013-10-06T21:08:31.204-04:002013-10-06T21:08:31.204-04:00I like this article for attempting to educate peop...I like this article for attempting to educate people about a possible risk. However, the article is wrong in some key ways. In addition, besides simply educating people, there is no point to this article.<br /><br />It has been mentioned several times in other comments that it is possible to have deduplication and still maintain encrypted data, so no need for me to reinvent the wheel.<br /><br />Overall though, does it matter? For starters, deduplication only works on common stuff, like an mp3 file, movie, etc. Do you think the unique hash of your personally written word document matches anyone else's word document in any way? Or any other file for that matter? So the only thing that actually gets deduplicated, is stuff that is not private at all. Secondly, if you have stuff that really does need to be so secure that you care so much, why are you even considering a cloud provider like dropbox without adding you own layers of security in?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-16750015.post-77123944091752925372013-06-01T09:06:15.525-04:002013-06-01T09:06:15.525-04:00Its possible to deduplicate without knowing the ke...Its possible to deduplicate without knowing the key. Before uploading, calculate a hash and compare it with existing hashes. To store a duplicate, store a link to the original copy and encrypt the link with the user's password. Or is there a flaw in this?iceman_wnoreply@blogger.comtag:blogger.com,1999:blog-16750015.post-42333609559440588552012-10-13T19:05:06.487-04:002012-10-13T19:05:06.487-04:00Dropbox installs a client on your computer... so t...Dropbox installs a client on your computer... so they have access to the plaintext version of your file BEFORE it gets transferred.<br /><br />It is stupid easy for the client to hash the plaintext file, send the file size and hash to the server to see if it's a duplicate of an existing file, and if it is just store your filename and a reference to the existing file on the server.<br /><br />This wouldn't be a performance improvement if dropbox had to go and decrypt everyone's files just to check if your latest upload is a duplicate. So clearly dropbox is storing your data encrypted, but an index of everyone's data is used for the de-duplication. Since file names are irrelevant to de-duplication, that index probably does not include filenames. But this has nothing to do with privacy, because the public does not have access to the index and, as someone else mentioned, if the government has a warrant they can search or seize your information on the dropbox servers regardless of their performance optimizations. <br /><br />If an attacker is watching my dropbox connection, de-duplication means that it's HARDER for an attacker to guess which files I am uploading, since duplicate files of any size become a small fixed size upload - they look the same to an attacker. And if I am uploading unique files, the attacker cannot know what they are anyway, unless he watched me download them from the web... in which case, he already knows that I have them without the use of dropbox.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-16750015.post-73761133489819044402012-09-20T06:42:17.355-04:002012-09-20T06:42:17.355-04:00Nice article:
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It says: Many users and even ...Nice article:<br /><br />-----<br />It says: Many users and even the technology press will not realize that AES-256 is useless against MANY ATTACKS if the encryption key isn't kept private.<br />-----<br /><br />Well, many users and even the technology press will not realize that AES-256 is useless if the encryption key isn't kept private.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-16750015.post-63575023737658352872012-07-26T17:24:18.045-04:002012-07-26T17:24:18.045-04:00Regarding Wuala: I'm speculating here, I haven...Regarding Wuala: I'm speculating here, I haven't use Wuala. Wuala stores the keys used for en/decrypting each file. Those keys are encrypted somehow with users' passwords.<br /><br />When you share a file with someone else, it's conceivable that Wuala might use public/private keys to encrypt the file key with the public portion of the other party's password-key without knowing that user's private password. Maybe that private key is encrypted with the user's password? Just a guess. <br /><br />Note that this does not require Wuala to store all the secrets required to decrypt anything after this operation is completed, so they still would be unable to do the deduping that Dropbox does. Also, it seems you can not recover a lost password with Wuala.ErikHaugenhttps://www.blogger.com/profile/10802814574934511523noreply@blogger.comtag:blogger.com,1999:blog-16750015.post-14620748088704611682012-06-26T15:24:45.462-04:002012-06-26T15:24:45.462-04:00I took a look at Wuala for comparison. If everyth...I took a look at Wuala for comparison. If everything is encrypted, and their people can't access the files because they don't have the keys- then how does sharing work? <br /><br />Does someone you share a folder with have to have your key?Marchttps://www.blogger.com/profile/02229607228674862682noreply@blogger.comtag:blogger.com,1999:blog-16750015.post-61475034547517031392012-01-13T16:50:29.668-05:002012-01-13T16:50:29.668-05:00I didn`t know that they can sacrifice users privac...I didn`t know that they can sacrifice users privacy, how can i find out if my files have been watched?filme pornohttp://www.ccmp3.netnoreply@blogger.comtag:blogger.com,1999:blog-16750015.post-27963332994327123382011-11-03T01:34:33.355-04:002011-11-03T01:34:33.355-04:00"If the hash value is provided by the dropbox..."If the hash value is provided by the dropbox client within the upload, but before encryption, files in the cloud ARE encrypted."—But, then if the 2nd uploader requests the file, dropbox would have to decrypt the file before sending it back, since the 2nd uploader would not be able to decrypt a file encrypted by the 1st uploader.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-16750015.post-18348022284141434302011-10-31T10:42:00.437-04:002011-10-31T10:42:00.437-04:00If dropbox deduplicates files on their servers, it...If dropbox deduplicates files on their servers, it doesn't mean they have plaintext access to them.<br /><br />Dropbox could simply compare hash values to determine if two files are equal, without knowing anything about the content. If the hash value is provided by the dropbox client within the upload, but before encryption, files in the cloud ARE encrypted.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-16750015.post-6969378957861434272011-08-01T15:58:54.766-04:002011-08-01T15:58:54.766-04:00@dimecadmoium: It's difficult to tell exactly ...@dimecadmoium: It's difficult to tell exactly what you are suggesting. I suppose you're right, that if it made sense for Dropbox to trust the hash generated by the client, then they would know they already had the file. However, that wouldn't matter much, since they would need the encryption key of the client that really uploaded it in order to send the file back to the other, new client.ErikHaugenhttps://www.blogger.com/profile/10802814574934511523noreply@blogger.comtag:blogger.com,1999:blog-16750015.post-83967084079706823442011-07-31T15:26:52.567-04:002011-07-31T15:26:52.567-04:00I'm curious as to how you KNEW they didn't...I'm curious as to how you KNEW they didn't md5sum (or similar) on the user's computer and then check for a similar sum (and maybe even size) on their servers. They wouldn't need the encryption key if that was done, but I see nothing addressing that fact.dimecadmoiumhttps://www.blogger.com/profile/13431491760379905103noreply@blogger.comtag:blogger.com,1999:blog-16750015.post-54796554770114870412011-07-14T03:35:41.033-04:002011-07-14T03:35:41.033-04:00@Richard2957
I disagree with your assessment. The...@Richard2957<br /><br />I disagree with your assessment. The real issue is not with the government or rights-holders being able to subpoena incriminating evidence, it's with Dropbox employees having access to sensitive personal information. When I signed up for Dropbox, they claimed that their employees had no way of accessing my data. Now I come to find out from a third party that the only thing preventing them from doing so is company policies. This is unacceptable. I replaced the "My Documents" folder with Dropbox and as such have many documents containing account numbers, SSN, etc located on their servers. Even if the employees follow their policies, that's no guarantee that someone couldn't access my sensitive info if the employee's login info or laptop were stolen/compromised. <br /><br />I will be researching how to encrypt all my data to Dropbox. I know of TrueCrypt, but did not find it very user-friendly when I tried it in the past. Does anyone know of any alternatives?David Chttps://www.blogger.com/profile/04306201665366956422noreply@blogger.comtag:blogger.com,1999:blog-16750015.post-35708264855402212392011-06-29T12:18:13.641-04:002011-06-29T12:18:13.641-04:00Wuala is a good swiss alternative (free for the fi...Wuala is a good swiss alternative (free for the first GB) develloped by a swiss University. With Wuala all your files get encrypted on your computer, so that no one - including the employees at Wuala and LaCie - can access your private files. Apparently the servers are in Switzerland, France and Germany.Sylvainhttp://ntdroit.wordpress.comnoreply@blogger.comtag:blogger.com,1999:blog-16750015.post-3955675366560858972011-06-02T11:44:09.254-04:002011-06-02T11:44:09.254-04:00The publication of this blog has done a great diss...The publication of this blog has done a great disservice to the shareholders at Dropbox and to the good citizens of the world.<br /><br />The only users who truly need to fear the Privacy issue are those that are breaking the law. I for one would be happy to see these people's privacy being broken by the relevant authorities. To me then the chance that child-porn and other illegal activities are placed at risk is a feature, not a bug.<br /><br />Dropbox offers an excellent service, and provides as good a security level as can be reasonably be expected from cloud storage. It would be a shame if their profitability was hit just so that criminals could have their lives made easier.<br /><br />But you got to pull readers into your blog, haven't you.Richard2957https://www.blogger.com/profile/05127369761381947767noreply@blogger.comtag:blogger.com,1999:blog-16750015.post-78592990264550873362011-05-21T10:11:13.271-04:002011-05-21T10:11:13.271-04:00Nice way of pointing out the completely obvious.
...Nice way of pointing out the completely obvious. <br /><br />Of course Dropbox has access to the contents of the files - you don't just need to analyze the de-duplication feature to see that.<br /><br />The public files link feature and the automatic photo galleries make that clear.<br /><br />I find it bizarre that you're kicking up such a fuss about something that most people knew about years ago. I guess you're just trying to make a name for yourself, but what a curious way to go about it.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-16750015.post-85075444068811513952011-05-20T12:17:22.065-04:002011-05-20T12:17:22.065-04:00The issue here is that they made a claim that simp...The issue here is that they made a claim that simply cannot be true, and so it would be better if DropBox just retracted the comment.<br /><br />I don't have a problem with how dropbox operates, whether the file is encrypted and the user password stored so the dropbox framework can decrypt content on the basis of dedupe, that level of access is acceptable to me..<br /><br />I would imagine in the instance of duplicated files, DropBox would decrypt the initial uploaded file, and re-encrypt it with a generic shared hash which is associated to all the other users, and I assume this shared hash would encrypted to each users own password so atleast at the raw user database level no two hash keys are alike - even for duplicated files..<br /><br />Also, most file systems have some kind of user access control which even at root level requires full access to the physical data in order to serve it. So just like on your corporate storage for example, you'll have standard users unable to access certain areas of your storage, but system level as well as administrators would be able to access all areas. <br /><br />I would atleast hope DropBox only allow root access to physical data and it's decryption at Platform level and only allow the core platform at the content owner real world access to it, meaning DropBox staff would NOT be unable to access the physical data because the user access layer in the DropBox architecture..Martyhttps://www.blogger.com/profile/12510425235048689919noreply@blogger.comtag:blogger.com,1999:blog-16750015.post-82343029036628716532011-05-19T16:50:18.143-04:002011-05-19T16:50:18.143-04:00And pray tell, where did Mr. Borenstein purchase t...And pray tell, where did Mr. Borenstein purchase the crystal ball that told him that people who protect their stuff "most often do so because they are breaking a law". Speculative nonsense.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-16750015.post-54597238346986525852011-05-18T18:35:58.121-04:002011-05-18T18:35:58.121-04:00CableCat says "if more people have the same f...CableCat says "if more people have the same file, they will encrypt it the same way" - but how do they decrypt it? Do they need any special information, like a password, to decrypt it? The point is that with deduplication, all parties "owning" that file have to be able to retrieve it. This means that passwords must not be necessary to decrypt files, since everyone only has their own password. So we can make the assumption that dropbox has the means to decrypt any file without the user's permission or knowledge.ErikHaugenhttps://www.blogger.com/profile/10802814574934511523noreply@blogger.comtag:blogger.com,1999:blog-16750015.post-59257757553343311642011-05-17T20:15:59.497-04:002011-05-17T20:15:59.497-04:00The point is that Dropbox made misleading claims a...The point is that Dropbox made misleading claims about their security. Fact.<br /><br />The point is NOT that you should know better than to believe a misleading claim. If you know better, good for you. But that does NOT relieve Dropbox of its obligation to make accurate claims about its security practices.<br /><br />Dropbox has revised its claims so that they are now more accurate. That is good. But many users signed up for the service, based on a flawed explanation of that service. This is not insignificant.<br /><br />The point is NOT that Dropbox is a bad service. Dropbox is an excellent service. It just does NOT provide exactly the level of service that it claimed to provide.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-16750015.post-38308523287802068742011-05-17T17:12:39.269-04:002011-05-17T17:12:39.269-04:00You can not assume that because deduplications is ...You can not assume that because deduplications is used, that the files are not properly encrypted.<br /><br />All you need to do, is to derive the encryption key from that data in the file. So each file is encrypted with its own key. But if more people have the same file, they will encrypt it the same way, and dedublication will work.CableCathttp://cablecat.dknoreply@blogger.comtag:blogger.com,1999:blog-16750015.post-60616836906540263222011-05-17T12:57:30.691-04:002011-05-17T12:57:30.691-04:00Also problematic is the fact that Dropbox's CT...Also problematic is the fact that Dropbox's CTO does not know how to spell a one-syllable word like "whoa."<br /><br />How can I trust a man to encrypt my data if he cannot spell as well as I could when I was in second grade?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-16750015.post-81363896674153024472011-05-17T12:52:55.778-04:002011-05-17T12:52:55.778-04:00Would be interesting to hear how you judge the sec...Would be interesting to hear how you judge the security of TeamDrive (www.teamdrive.com). Does it go beyond the security of SpiderOak?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-16750015.post-32809924240134307322011-05-17T09:30:26.927-04:002011-05-17T09:30:26.927-04:00Any thoughts on the security & reliability of ...Any thoughts on the security & reliability of CrashPlan? I love the service, and the fact that you can also backup "free" to other computers you own, or to friends who want to share space with you. The pricing plan is also in line with SpiderOak, but obviously CrashPlan is backup-only (no sync, etc).Anonymoushttps://www.blogger.com/profile/07994045859158986001noreply@blogger.com