Screenshots of upcoming Mega site: key generator, registration, and file manager

http://thenextweb.com/insider/2012/12/07/kim-dotcom-posts-screenshots-of-upcoming-mega-site-key-generator-registration-and-file-manager/

by mtgx • 14 years ago

40 32 14 years ago

thenextweb.com

anonymous• 14 years ago

That key generator seems to imply javascript-based encryption. The only possible use I can see, is encrypting a file on upload, so MEGA's servers can't look inside. In which case I'd very much insist on having an open-source desktop client, instead of entrusting encryption to some javascript code which can be hijacked.

nwh4• 14 years ago

Even if the encryption is using a known-good algorithm, there's absolutely no way for the JavaScript client to generate anything close to a cryptographically secure random string for the key.

Unless they use random numbers supplied by Mega itself, I just don't see how that would work. If they are using entropy supplied by Mega, then they might as well not bother with the whole encryption thing.

ED: The screenshot does mention that they gather entropy via keystrokes and mouse movements (like modern OS do), but I'm still not sure that would provide anywhere near the randomness needed.

daeken3• 14 years ago

> Even if the encryption is using a known-good algorithm, there's absolutely no way for the JavaScript client to generate anything close to a cryptographically secure random string for the key.

The WebCrypto proposal includes a CSPRNG -- I believe it's now implemented in Gecko and/or Webkit (don't recall which one I saw). However, the bigger concern is that the JS is coming from their servers, which means it's completely compromised by default.

onli4• 14 years ago

Why? The screenshot mentions RSA-2048. At which point of that algorithm is random input so important that it breaks the encryption if you don't have access to a true random number generator?

I know that you choose p and q by random. And it is obvious that you want to choose numbers that an attacker can't easily guess. But not having access to a hardware number generator doesn't automatically imply you have a real useable vulnerability here, or does it?

Osiris• 14 years ago

I recently switching to Braintree Payments and they have a Javascript client-side library for encrypting the credit card information before sending it to my servers.

As they explain it, they use a private/public key encryption in which the server has the private key and the encryption occurs with a public key. Only the private key on their servers can decrypt the file.

Could they be using something similar where you generate your own large (2048 bit) key and use that repeatedly for each file that you upload? Could they allow the user to supply their own cryptographic key that can be generated with local tools like openssl?

I'm no cryptography expert, I'm just curious what they could do to make it more secure.

SideburnsOfDoom• 14 years ago

Does Javascript-based encryption imply Javascript-based key generation? Key generation could be done on a server despite the presence of a progress bar in the web client. It doesn't have to stay only the server, or even be kept on the server at all.

Actually, all the screenshot is showing is Javascript-based entropy gathering. It does not demonstrate that any of the other steps are necessarily done on the client.

kapnobatairza• 14 years ago

Can someone explain to me the difference between the new Mega and something like SpiderOak?

schabernakk• 14 years ago

Judging from the past I would guess that Mega will be quite popular in the web-warez scene as a hoster.

buro9• 14 years ago

Who holds the private key?

Do you trust them?

wmf2• 14 years ago

Who holds the private key?

You do. (Or in reality, the whole world since the point of Mega is to share files.)

Do you trust them?

Depends.

ericbb• 14 years ago

> You do. (Or in reality, the whole world since the point of Mega is to share files.)

That implication makes no sense to me. Why would you ever share a private key?

The trust question is more about public keys. Do you trust that the key you think is your friends public key really is? And that's what key-signings are for.

The screenshot shows in-browser key generation but there's no reason I can think of that they should not accept keys generated by GPG or similar. Generate your keypair as securely as you can and however you like--and then only submit your public key to the Mega site.

phpnode2• 14 years ago

I think most of the responses here regarding the crypto are missing the point. It doesn't matter if the key is not totally random. It just has to be good enough so that they can plausibly deny that they know anything about the file contents. It is their attempt to absolve themselves of responsibility for the copyright issues concerning the content. It is not about making your files more secure.

res0nat0r• 14 years ago

How is this new service supposed to be viable like the last MU? If the point of this "encryption" is supposed to provide plausible deniability, then the whole point of distributing warez via this site "legally" will have to be that the decryption keys are kept secret or underground.

But for this site to be popular enough to allow for downloads supported by ad revenue, then the file links and decryption keys will have to be widely distributed to drive traffic. If someone files a takedown notice with a file and decryption key that proves the data contained therein is copyrighted then won't MU be in the same boat they were in previously?

phpnode2• 14 years ago

they could be doing something as crazy as putting the key in the "share this" URL. If they put it after the fragment then it doesn't get sent to the server and they can continue to deny having the ability to read file contents. Someone did a "Show HN" with a site that did something similar a month or two back.

Presumably mega then don't offer a site search but instead rely on google to index warez forums with links to the site that include the decryption key. I don't know.

Edit: found the site that did this: http://news.ycombinator.com/item?id=3852649

4ad• 14 years ago

I don't think this encryption is supposed to provide plausible deniability in the most general sense. Stuff was DMCA'ed from megaupload all the time, but that was never a problem. There were many many many uploads of the same data and you could always find a working copy. There was a lot of friction because some people wanted all copies to be deleted, not just the link removed. This encryption allows for plausible deniability against deduplication. Mega can't possibly know what are all the copies of some content, so even if they comply with DMCA requests as before, nobody can force them to delete all provided copies.

Screenshots of upcoming Mega site: key generator, registration, and file manager

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