No, don't enable revocation checking
imperialviolet.org
imperialviolet.org
[0]: https://github.com/openssl/openssl/commit/731f431497f463f3a2...
Revovation isn't perfect and I would not suggest the current status quo is OK but the intermediary approach Chrome takes cannot be trusted as they have now shown.
If Chome will not show our cert as revoked what is the point of revoking the cert? The author has points but the approach Google ie taking is a cure worse than the disease...
Believe me I am aware of the limits of soft-fail, but the answer cannot be even in the short-run to let a browser vendor tell us which revocations are worth knowing about.
Which approach is worse?
So you trust the browser vendor to ship you executable native code but you don't trust the browser vendor to apply reasonably decent criteria for the top x% most-needed cert revocations on the Internet?
It might be ok if used in addition to checking revocation lists. However why should a bank get to have their certificate in the crlset but a saas provider not? Or do you really trust Google there?
Frankly Adam doesn't really believe revocation is pointless. If he did, he wouldn't even suggest that sending a valuable subset of certificates to the browser in a batch is any sort of solution at all. All that does, though, is create a two-class secure internet: those entities Google deems worth distributing revocation information for and those not. That isn't a solution to anything.
So is getting a subset of revoked certs Google deems "valuable." In fact, that may be even more dangerous since it establishes first class secure sites vs everyone else.
Why should Yahoo's cert revocatins get in the CRLsets but not less well known sites? How is that less broken than online revocation?
Keep in mind, my big objection is:
Google did not distribute our certificate vocation in their CRLSet, presumably because we weren't large enough. That is not a fix for anything.
I would be OK if they guaranteed complete CRLsets from all participating CA's. Since they don't, their solution is more broken than what they are replacing.
So I acknowledge that online revocation is problematic. I just think the crlset approach is an order of magnitude worse when the crlset is a subset of revoked entries sent by the ca.
With the talent & resources that Google has, or the talent & resources that Mozilla has, or the talent & resources that Microsoft has, this should have been better solved, in a way that works for all TLS-reliant applications, years ago.
Using Chrome's built-in auto-updates to make a subset of "high-value revocations" work, at a daily frequency, for Chrome users only, is not a very web-friendly solution.
It's like a gated community hiring its own rent-a-cops... maybe that's an improvement for the fortunate ones on the inside, and maybe a necessary stopgap. But to people outside that perimeter – like someone whose revocation doesn't make it into the Google CRLSet – it feels like an abdication of duty by the web's stewards.
Adam has been pushing the state of the art in cryptography in the practical realm for years, and your criticism is "They should have just solved this problem better! They should just pull their finger out and get working on it."
Making a real difference in the chaotic realm of standards bodies and browser vendors is a lot harder than it looks. Adam has an impressive track record for actually improving internet security for users.
Where's your suggestion for how revocation could be solved better and implemented in a practical way? I don't see you rolling up your sleeves to get the actual work done.
Yes. It has been for a long time. Long term, we want to figure out ways to improve thread quality. Not so much in terms of the toxicity problem, which has seen some progress lately (we hope), but the arguably harder problem of voluminous uninformed commentary clustering around the mean. If you (or anyone) have any suggestions, I'd love to hear them. hn@ycombinator.com is the best place to send them.
(This is not about any particular comments in the current thread, only the problem in general.)
(Might it take a product-liability lawsuit, where somebody suffers financial loss because Chrome is deceptively showing the "secure" indicator even for certificates revoked days/weeks/longer ago?)
Consider the CRLSet approach. Maybe it's the best any browser-maker has done, and a useful learning-exercise for a future industry-wide fix. But it still sucks. It's capped at 250KB, assembled via an opaque editorial process, only refreshed daily, only protective of Chrome users and some chosen subset of "high priority" certificate-revocations, and still vulnerable to an arbitrarily-long attacker embargo against the Chrome update servers. Langley himself mentions it can't scale to the recent need for higher-volume revocations.
Compare it with Google's own "Safe Browsing" blacklist system. That delivers megabytes of compressed privacy-protecting blacklists, constantly refreshed via incremental updates to maintain a freshness of under 45 minutes, in a manner available to all browser makers.
So a potential version 1 of a better approach: leverage Safe Browsing to deliver fresher certificate blacklists to more end-users, and also warn users (not just silent-fail) if they're making 'secure' connections but are too-many-hours behind the best available revocation information.
I sketched a few other possible next-directions in a prior comment, https://news.ycombinator.com/item?id=7584458
However, the implication that I, as a lone individual, must "roll up my sleeves to get the actual work done" for my words to have weight here is both nonsensical and (speaking of rhetorical cancers on HN) unnecessarily personal. Google, with plentiful expertise and cash, is shipping the world's most popular browser – but that browser has multiple inadequate certificate-revocation systems. Yet I should be contributing my expertise to fix this before I may speak? "Christ", that.
Meanwhile, you've offered a "sketch of a solution" that involves CAs (a) cooperating with Google and (b) employing computer science in the pursuit of writing actual code. Why not talk to Comodo and see how likely that is to happen?
You know who thinks CRLsets suck? Adam Langley. Certificate revocation is broken. They did what they could. Google didn't design SSL revocation.
All Google has done is orchestrate the adoption of TLS forward secrecy, fixed security vulnerabilities (for many years running) in OpenSSL (along with virtually every other component to modern web browsers, along with ffmpeg and the open source video stack), invented and deployed browser certificate pinning, spearheaded the deployment of Certificate Transparency, oh, and found/fixed Heartbleed.
But, I'm sure your comments are great. Why not take them to the IETF TLS WG? I'm sure you'll find an eager audience. I am not kidding.
Similarly, CA buy-in is not a blocking prerequisite for a better approach — it's just another excuse for inaction. Exactly as with CRLSet, the browser vendor can say, "we'll scrape your revocations where we can find them, or you can provide them this way". Then, if an incompetent or recalcitrant CA hides their revocations, it's an issue between the CA and their harmed customers.
It's great you, me, and Adam Langley all agree that revocation is broken, including Google's stopgap proprietary solution. But hasn't everyone understood that for 15+ years? Why isn't there a fix?
The browser makers absolutely own responsibility for this, because they're the ones that show end-users a security indicator. They're shipping the software that creates a risk, they can unilaterally fix this on their own initiative, and they're not so poor or stupid that fixing it should be beyond their capabilities.
Yes, Google has done a lot for security. Their 'web security karma' is very net-positive. They still deserve a demerit, along with Mozilla and Microsoft, on this particular issue.
Referring this to the IETF for standardization is just another way of excusing more inaction and delay.
You can blame the browser makers as much as you want, but among them as a group, nobody has worked harder on making TLS better and safer than Google. But here you are berating them for the effort.
I can applaud Google's efforts in general yet still point out when there's one egregious, embarrassing gap. They are one of the only three institutions worldwide that could possibly fix this for users, and I'm not picking on them over the others.
Here's the thing. I have been advertising the impact of this decision by Chrome on our SaaS business. It just isn't acceptable that cert revocation means one thing if you are Yahoo but another if you are a startup SaaS business.
As I have said repeatedly, this is a way to ensure that things are comfortable enough for the people at the top that everyone else is sacrificed in the name of it being too much trouble, working for free, etc. But as long as the big sites are protected by Google, nothing will get fixed and us smaller competitors will be screwed.
I am sorry, but that's just morally wrong. And it is the major reason I now recommend Firefox over Chrome.
I don't think it is just a question of pretending. It is a question of making sure that everyone is in the same boat security-wise so that the root problems in fact get addressed.
What Google does is make Amazon more secure and the small SaaS provider less so. And it makes sure that the big providers have less incentive to fix the underlying concerns.
Isn't CRLSet a Google invention? Doesn't it depend on Chrome software updates?
All I know about it, I read from Langley's writings. Is there a better reference?
Who set the implemntation limits, if not Google?
Maybe those limits are justifiable, but that doesn't leave someone who's left unprotected, by what seem like arbitrary policy cutoffs, feeling any better.
Google didn't invent this idea. It was suggested by the CABForum.
CRLsets are static, practically hardcoded revocations that every installation of Chrome receives. The idea that https://yourblog.com should expect specific consideration in Chrome updates is about as reasonable as suggesting that we revert back from the DNS to host files.
The more I read, the more it seems CRLSet implementation choices were entirely Google's. For example, when CABForum members want information about how CRLSets work, Langley suggests the best (and only!) reference is the Chrome source code:
https://cabforum.org/pipermail/public/2013-August/002149.htm...
I am of course open to better information. But for now it still looks like Google did indeed "choose how big to make the lifeboat", unlike your assertion to the contrary.
Also, it looks like the 250KB cap is in Google's unpublished server-side source that constructs the CRLSets. So Google could conceivably "expand the lifeboat" unilaterally with a tiny edit!
For reference, it appears the current 'Safe Browsing' blacklists, never more stale than 45 minutes, are about 2.3MB in size. So the CRLSet cap (250KB) and freshness (1 day) aren't very generous to users.
The person upthread unhappy that Chrome didn't pick up their revocation (einhverfr) isn't worried about a measly blog, but their SaaS business.
If 2.3MB isn't enough to protect everybody, make it 23MB or take whatever other design steps are necessary. The world's most popular browser, from the world's most profitable internet company, in 2014 shouldn't be showing the lock-icon and "valid certificate" hours/days/weeks after a publicly-available revocation.
"Manual curation", rather than being impressive, is a design-smell here. And none of Google's work to outcompete other browsers, using proprietary Chrome features, is being done for me "for free".
Great. Maybe now, when half the internet is already compromised and all our certificates are not worth the bytes they're made of ... maybe we should try to come up with something better.
edit: Actually, this whole heartbleed affair has been quite eyeopening for me, so I'm thankful for that. But it certainly didn't help with the paranoia I feel the last couple of years while using services on the internet.
Why not other ways to rapid-broadcast invalidity in censorship-proof ways, so that a browser encircled by an enemy can quickly figure out something's wrong? (Or, why can't security professionals get around interdiction as effectively as copyright pirates do?)
I'm quite fond of how the SSH host key system works.
Prompt me the first time I see a new key, provide me with supporting evidence (e.g. show me how many people have previously accepted this fingerprint for this domain) and alert me the same way in the future if the key ever changes.
If the 'supporting evidence' was plugin-based then this system could quickly become more user-friendly and trustworthy than the current centralised system can ever be.
There could be plugins to automatically trigger a SMS challenge on first contact with particularly sensitive sites. Multiple competing P2P web-of-trust plugins, plugins that let you follow trust-lists from third parties, etc.
In the current system you rely on a single, very questionable opinion on the trustworthiness of a given certificate. In the new system you'd be presented with a trust-score compiled from a whole range of opinions. The sources of which you chose before-hand.
Of course this approach doesn't include a license to print money for corrupt CA organisations and is not going to happen for that reason alone.
The point is that once this seed trust has been established, which ideally would need to happen only once in your lifetime (given proper sync/backup facilities), you gain actual control over who you want to delegate your trust to, if at all. On a site-per-site basis.
If an american, a chinese and an EU database independently agree on a fingerprint for a site then that would be an actual trust indicator. Very much unlike the perpetually compromised zoo of certificate authorities of today.
And obviously once there's a market for plugins you'd quickly see plugins going far beyond what we get to know today (read: essentially nothing). There could be subscription-based plugins providing detailed information about the remote party, down to credit ratings, company history, you name it.
Or are you suggesting every browser will contact many of its personal web-of-trust sources on every secure-connection? Without additional innovation, that seems just as prone to the performance bottlenecks or soft-failure (on stale data or blocked connections) as the current system.
For Hacker News? No.
For my bank? Yes, absolutely.
The implementation of a fast and scalable lookup is not exactly rocket science (cf. DNSBLs). It's a political problem, not a technology problem.
Yes, revoke is broken by design, especially with mobile and Chrome browser. I'd say it's broken everywhere except Firefox with OCSP Hard Fail enabled.
Thanks to this flaw StartSSL business model has become somewhat outdated IMHO with the free certs and paid revocations.
I'm dreaming that we can fix the revocations issue with 24hour valid certificates. Suggested at the end of my post.
But I must be naive on this as it's too simple, just haven't found the flaw in this myself. Yes, it needs technical orchestration, but at least it does not add extra layer of single point of failure for every session.
EDIT: Just finished the OP post and it does indeed also mention "short-lived certificates" in the end as a potential solution.
Short-lived certificates were explored in Towards Short-Lived Certificates http://crypto.stanford.edu/~dabo/pubs/abstracts/ssl-shortliv...
Without certificates, SSL/TLS falls apart.
Perhaps a better use of CAs would be to always delegate authority to the domain owner -- we'd only need OCSP for the CAs, and domain owners could issue hour/day-valid certs via a cert infrastructure. That would push a lot of complexity down to domain owners, it would probably lead to a lot of errors in implementation -- but those errors would only affect the domains -- not the main CA trust chain as such.
I'm not sure if that would be an improvement or not -- but at least you could know that if a domain was run correctly, a valid certificate could actually be trusted...
> "conceding the CA PKI to world governments" is your idea of "better use of CAs".
China Internet Network Information Center (CNNIC)
Government of France
Government of Hong Kong (SAR), Hongkong Post
Government of Japan, Ministry of Internal Affairs and Communications
Government of Spain, Autoritat de Certificació de la Comunitat Valenciana (ACCV)
Government of Spain (CAV), Izenpe S.A.
Government of The Netherlands, PKIoverheid
Government of Taiwan, Government Root Certification Authority (GRCA)
Government of Turkey, Kamu Sertifikasyon Merkezi (Kamu SM)
Hong Kong
[^1]: https://blog.mozilla.org/security/2013/12/09/revoking-trust-...
[^2]: https://www.mozilla.org/en-US/about/governance/policies/secu...
[^3]: https://www.mozilla.org/en-US/about/governance/policies/secu...
[^4]: https://social.technet.microsoft.com/wiki/contents/articles/...
Ultimately, the URL bar needs to go away. More fundamentally, the asymmetric relationship between very large organizations that authenticate their identity with browser CA certs, and individuals who authenticate their identity with passwords needs to change.
Cryptographically generated addressing schemes like Telehash can do the automate-able stuff better than the current CA situation. The problem (and solution) I'm struggling to articulate involves the fact that granular authorization systems and trust databases need better UI before we can really fix this.
I suspect cheaper hardware tokens will play a significant role.
CAs already provide the same trust infrastructure, but due to incentives do not sign delegating certs by default, but typically charge extra for certs that allow the owner of a domain to set up their own internal CA.
DNSSEC only works (reasonably) for TLDs where DNSSEC is implemented, and when DNS resolvers implement checking -- many ISPs don't. Delegating CAs are already part of SSL/TLS.
DNSSEC requires fidling with the DNS information -- delegating CAs, while requiring issuing certs, only require configuration of the various services (web, imap, smtp etc) -- as per usual.
For delegating CAs to improve the security of any given domain -- some infrastructure would be needed to set up an intermediate CA. I guess for small organizations, OCSP wouldn't really be needed, as the CRLs would be small (assuming different CA for public facing services and stuff like personal certs for users). Another option would be to simply roll certificates frequently.
Certificates bind a public key and an identity (commonly a DNS name) together.
...when issuing certificates a CA validates ownership of a domain by sending an email, or looking for a specially formed page on the site.
So, if "DNSSEC secures DNS," as you say, why do we need certificates at all? Considering that the CA already depends on DNS to issue (many) certificates, why not cut out the middle man and simply publish the domain's public key in a DNS record? What actual value does a certificate offer other than that? I'm genuinely asking, because I'm curious if DNSSEC provides a way for a domain owner to establish trust in the domain's DNS records, that cannot be tampered with by the domain's registrar.
If we could replace LDAP with something a lot simpler, we could as replace X.509 with something a lot simpler (LDAP is a mildly simplified version of X.500, of which X.509 is a very closely related OSI legacy standard).
So DNSSEC doesn't go far enough. IMO, we should be working on ensuring that it can be extended to allow for certification of hosts, etc. However, at present it doesn't do this very well.
The problem I still see is creating a global directory of Kerberos realms. There still needs to be a sneakernet component for private key distribution. (Maybe that would be a better use of the armored cars I see making regular stops at the banks around town.)
From there it should be quite possible to tie public keys to hosts all the way down since you now have a chain of trust. Should be trivial, but the problem is that I don't see how to get the root zone to publish domain keys.
Yes, that replaces CA's with domain registrars, but that is a healthy trade. Since you would get keys (all allowed keys!) all the way down with your query, you wouldn't need to check revocation because you'd know the keys before making the connection.
From a user's perspective, "my bank" and "your bank" might be the same thing, or they might be different. When I care about verifying the identity of these things, why not just go to the source? I can do key exchange every time I visit an ATM.
I can imagine using DNS with multiple contextual root namespaces, with the trust anchors being managed by more direct human relationships. This wasn't feasible when the systems were originally designed, but now we can put public keys in jewelry. Keychains on our literal keychain.
>
> So, if "DNSSEC secures DNS," as you say, why do we need certificates at all?
Yes and no. Note that a cert binds an identity, not just a DNS name (but that is what is needed for web servers).
DNSSEC doesn't work without resolvers checking for the DNS keys, and it's not immediately clear (to me at least) if the various higher level clients can transparently detect if a DNS name is secure or not (similar to how a web browser can't tell if it's accessing a resource over a secure IP based VPN and can therefore safely transmit credentials via plain auth).
For trust to work, there needs to be integration of the chain of trust all the way from the user to the server. TLS/SSL already provides this -- and with delegation the infrastructure is in place for owners to manage trust for their own domain (and it is already possible, but typically expensive).
In it's barest form DNSSEC only makes DNS secure, which prevents DNS spoofing. If you also place a cert (could be self-signed) in DNS, then you have a "full" solution to securing communications. You would be able to download the cert without DNSSEC, but unless the chain of trust of the cert could be verified some other way, you wouldn't be able to use that cert for secure communications.
It is true that current CAs bind a cert to a domain name, but it's not really the domain name part that is interesting, it's the entity identifed by that name. So your browser can say, I don't care where this authenticated (and encrypted) data stream is comming from, I just care that it is backed by example.com (that is backed by example-ca.com) -- and if the user thinks that Example corp. owns the example.com domain, one can then infer that the browser is really talking to a web site set up by Example corp -- regardless of which IPs and DNS records are involved.
Keep in mind that the same CA infrastructure allows a user to indenify to a server as user@example.org -- from any ip or doman name -- just as securely, via mutal trust in "Example CA". I think it's somewhat unfortunate that DNS is so tightly integrated into the user interfaces for the web -- asserting things about IP adresses and DNS names isn't really all that interesting -- it's asserting things about entities that is interesting.
While I'm no fan of the current CA system, I'm not convinced DNSSEC is securing the right things at the right protocol level(s).
One problem might be that the 0.1% of sites hit by the false positive effectively couldn't use OCSP stapling but Chrome could just first call back to Google as a CRL proxy to avoid making an OCSP request when the site stapled a valid but potentially revoked OCSP response. Then just store that response from Google for current version of CRL in the cache. End result is that the unlucky false positive sites don't have tons of unnecessary (unnecessary as far as the OCSP spec is concerned) OCSP requests going to the CAs and the only thing they would notice is that a new visitior takes 100ms longer to make the first page load.
And through the magic of bloom filters if you wanted to bump the false positive rate down to 1 in 10,000 it only bloats the list to 1.14MB. Furthermore, there are methods to make the bloom filter scale-able such that a client doesn't have to necessarily download the whole bloom filter again if a bunch of elements are added to it and instead just download a portion of the data required for a full update.
The more I think about it the more I wonder why this isn't already in Chrome in some form or another. The only downside is weird networks where OCSP might be filtered, but not https, and access to Google is filtered.
Edit: One thing I feel stupid for overlooking is that Bloom filters aren't cryptographically secure so an attacker could theoretically find a serial number for some CA that would cause a site to always be a false positive but I don't think any CAs are still giving out serial numbers in a predictable way after the MD5 debacle and even if they were it would seem to be impractical to me. The fix would just be do a SHA256 hash of the serial instead of the serial itself.
I got the idea from Squid and the network of caches.[1] That body of experience may be helpful.
For shrinking the size, RLE might work (most entries would be 0), and rsync may reduce bandwidth. It looks like the Squid network just used http requests for refreshes. There's probably a sweet spot for bandwidth, and I'd guess that 90-99% would work fine; you're balancing the size of the continually updated bloom filter vs. the requests for certificates that match it. I didn't worry about false positives, because it could just send an OCSP query in that case.
Your numbers for revocations sounded very low, but I just used crlset-tools[2] and checked, and it's about right. Which is weird, because someone else[3] mentioned a size of "4.107Kb" at version 1567, but that's somehow different - compression, perhaps. I thought I'd heard about CRLs megabytes long, but Google Chrome seems heavily curated re: CRLs.
I'd hash over signatures instead of the oft-predictable serial numbers, as you noted.
[1] http://wiki.squid-cache.org/SquidFaq/CacheDigests
[2] https://github.com/agl/crlset-tools
[3] https://scotthelme.co.uk/certificate-revocation-google-chrom...
> if the attacker still has control of the site, they can hop from CA to CA getting certificates. (And they will have the full OCSP validity period to use after each revocation.)
The solution here is to not allow OCSP stapling to request a new certificate and use a full OCSP check to verify that the cert wasnt revoked.
Systems like Namecoin could serve this purpose marvelously. Powerful devices have direct access to the entire cryptographically authenticated DNS and certificate database. Weak devices can specify whom they trust to provide them with DNS/certificate data, and even those devices get some cryptographic security guarantees thanks to technologies like SPV.
Namecoin is fantastic in theory, but has the fatal flaw of using Bitcoin: the fastest number cruncher wins. Some would argue that the strength of Bitcoin's tech is that numerous currencies with different genesis blocks can flourish. That doesn't get us anywhere with naming, though.
Dead horse flog: the CA model's problem is that you can't do federated (global) naming and federated trust in the same system.
What's the issue with that? It's reasonable to assume that the good number crunchers will always have more power than the bad number crunchers, and if that assumption ever fails, it's easy to detect and we're simply back to CA levels of security.
Environmentally, that number crunching is a colossal waste of energy. We don't need to base our entire economy on that kind of energy footprint just because we occasionally want to make anonymous global barter convenient.
I should be able to choose who I trust, a notary system would allow me to do just that. No central CA systems.
The biggest concern I can see is Identity management, but, as mentioned by Moxie, most of these CA don't do anything close to proper Identity management any more - I have a number of certificates bought from quite a few different CA's all made out to my rabbit, at no fixed address.
Notaries can, of course, do additional verification - they could even advertise this as a premium.
I don't see why this can't be extended to DNS lookup's either. I trust X notaries and pin the results I get, I can choose to trust a majority, or be hyper paranoid and require everyone to agree. No need to run a power hungry blockchain, no single point of technology failure.
Technically, all of that is feasible today. And I imagine we will see a number of different technologies combined to form a proper, decentralised, system.
The web, as a technology is probably not going anywhere for a few more decades at least - people have gotten very used to opening up a web browser - very few actually understand the technology beneath.
The CA/DNS issue is one based solely around them - can I type the domain name I saw on the tv/ my friend gave me/I heard about into a web browser (and these days) and it can direct me (securely) to the page where I can do business.
Telehash seems to fit in on another level. Perhaps one which we are heading towards - a world of machines securely finding and communicating with each other to achieve a goal set for them by some human actor.
This space is becoming more crowded and no good contender has emerged - and I think there is a good reason - they are either too radical as so they can't find a footing, or they are too conservative.
The documentation is slightly lax, but I feel telehash is the latter - it doesn't seem to be solving any problems already solved:
* Space/Storage/Data Transfer - I don't care what anyone says, the blockchain model is simply no scalable, any system where are full client has to hold onto/download gigabytes of information is a non-starter for me.
But still, in any new system - hopefully decentralised, we need to distribute information. Any kind of system we build must be tolerant of partitioning - I think the solution to this is injecting some trust (ala Convergence)
* Speed - Computers work in nanoseconds, the web currently operates in seconds (some sites in milliseconds) - we can't beat the speed of light, but we can certainly start removing the cruft from our communications - HTML, XML, JSON, CSV - are all formats designed for people. We need tools that let us manipulate formats designed for machines.
Our networking protocols are like this as well - as much as people hate ASN.1 it solved some problems decades ago allowing the phone system to scale on just duct tape and wd40
* Power - Blockchain bashing time again - we live in a world of limited, expensive power. We are getting much better at producing low power devices, people like wireless devices. Why should our networks be so power-hungry?
Just a few, rambling thoughts.
There's no blockchain involved in Telehash. It accomodates various cipher sets, including one suitable for ultra low power devices (there's a partially working implementation for Arduino). And you're correct, it isn't really aimed at enabling anything like trusting a URL from a television commercial.
Telehash is conservative in the sense that it solves useful problems, even within the current DNS infrastructure. No one's currently doing this, but you could easily map a DNS name to a Telehash address. But it also offers global resilience to partitioning, because the logical mesh can operate on any lower level network transport.
I like the multiple notary model of Convergence, but I think any of these trust models still need to separate the "human memorable names" component.
I guess, I still don't understand the point of Telehash. Even having read through the documentation. "Establishing private communication channels" is definitely a big problem, one with a huge threat model, and the solution is probably multi-faceted - I don't see where a system like Telehash fits in v.s. something like tor or i2p for example - does anonymity fit into the threat model?
Before dragging this thread off the page I will follow up with an email. :)
Telehash's design may simplify the future design of Tor-like protocols, but anonymity is not an intended core feature.
Partition resistance is probably the highest priority. If any possible insecure network path exists, encrypted communication between endpoints should also be possible (and automatic).
* sayI [http://www.ethos-os.org/~solworth/sayIgroups-20130614.pdf]
* MinimaLT: http://eprint.iacr.org/2013/310.pdf
* CurveCP: http://curvecp.org/
Telehash started out life as a more generalized global DHT-for-your-apps design circa 2010, and the spec has since evolved significantly to include the same kind of wire-level crypto.
Opening an issue is the easiest way to get the FAQ updated (and we'd definitely appreciate the feedback): https://github.com/telehash/telehash.org/issues
How do you figure that Namecoin is a "single entity"?
Contrast with something like Convergence, where, while they share a common protocol (maybe...not necessarily) each part is responsible for itself, and not tied to any particular larger whole.
If you can answer that without trust. .
But it isn't for the main areas of SSL usage (e-commerce, ensuring your passwords are sent to the right party, etc). Those require trust. I don't know how you get around that.
I.e. I can imagine the concern being that X.509 ties together validating identity with public key infrastructure but since one use of a public key is to validate identity I am not convinced that is a bad thing, and to be honest, I can't see a trustless alternative for most of the current uses.
I can imagine many better alternatives to X.509 (anything that starts with a letter . three digit number is OSI legacy crap), but I don't see how to get rid of the identity vouching aspect of it.
Most people honestly don't go to the effort of verifying that a certificate matches the real-world identity they think it does. It's difficult, especially with smaller stores that don't use EV certificates.
For cases where people think third-party attestation is a necessary thing for their purposes, frankly, we have nothing better than the CA model right now; but that can easily be integrated with Namecoin, allowing for only those who need it to use it, and the rest to have access to secure communications and proofs of digital identity without having to pay up.
Do you know if there was a specific reason or were people just not interested/none of the browsers jumped onboard?
Personally I think now is good time to revisit assumptions made a few years ago - security and privacy and in particular non-government controlled systems are on many peoples lips.
If I ever clear my current plate, I would be interested in diving into the problem.
"Convergence is blocking on TACK, which is blocking on browser vendors."
Convergence had the momentum, and there was a small but vocal group of people willing to support it. But, due to project mismanagement and lack of communication, that momentum has been lost.
TOFU/POP is not an effective model for the web. There are simply too many sites for it to be useful. It's pretty much an everyday occurrence that I go to a site I've never been to before, and certificate pinning won't help at all there.
I am aware of both names, thank you.
>That only has to happen once for Google to put a gun to the rogue CA's temple.
Google can't really help in every single case. There are many situations where Google's revocation scheme can't keep up.
You also have to put a lot of trust in Google. You think Google is going to issue a revocation if they're under legal pressure not to?
As you are aware, human factors are frequently the weakest parts in a cryptosystem.
But it's unsuitable for the entirety of the web. You can't hardcode all certificate fingerprints of the whole internet inside the browser.
>> The migration away from the CA model is called "certificate pinning".
> key continuity destroys the incentive to attack sites by compromising CAs
We need to ELIMINATE CAs (CA as in some third party (google, Verysign, GoDaddy, ...) who you have to trust). The whole concept of trusting a CA is broken, and pinning does nothing to address that, at least not in the proposed TACK implementation.
I really feel the correct step forward is Convergence or Perspectives. If just browser vendors would jump in, we could use it right away. Mozilla/Google could set up a few notaries and set them as trusted by default in the browser. They choose the CAs they put in our browsers anyway, so we trust them already. That trust could be implemented with notaries instead of the CA model, so if someone wants to setup their own notaries they can.
What's your take on this? I value your opinion on security matters.
The biggest security problem on the Internet isn't protocols and it isn't cryptography. It's that the UX the browsers have for managing/configuring Internet trust hasn't changed since the late 1990s, and it's buried 3-4 levels deep in the "no user serviceable parts" section of the config UI. There are a lot of very productive things you could do for Internet security simply by revamping that UX, without making a single wire-level change to the TLS or HTTP protocols.
Does Namecoin actually work like that? If so, is there a similar alternative that doesn't?
Also, certificate "whitelisting" could be a part of the DNS protocol itself (return the IP address of the requested hostname and the hash of its current, valid certificate).
Something has to give. We need to abolish SSL/TLS and migrate to something that isn't broken by design
It's not the Internet, just the CA system. There are better systems for handling trust out there, for example, people have been signing each other's PGP keys at key signing parties for decades.
Ok, so it is just the portion of the internet that involves purchasing things with credit cards and requiring passwords to access sites. The rest of the internet is just fine.
Great. I thought for a moment that the commercial basis of the internet might be in danger. Now to determine what percentage of the internet is not dependent on the CA system.....
Sorry, but after the last few weeks I'll happily accept a little slowness for the security revocation checking provides in the cases where it does work, even if it's not 100% of the cases.
Doesn't mean there are "no" cases where it works. It just means any attacker dedicated enough can work around the CRLs.
I don't see any reason why one should throw the baby with the water. In this case, I just see Chrome guilty of FUD and hiding behind an intractable problem to justify their incorrect position.
See http://en.wikipedia.org/wiki/Two_Generals'_Problem if you want to convince yourself the problem is intractable.
> "In order to end on a positive note, I'll mention a case where online revocation checking does work..."
To deal with captive portals: have an SSL signed 'subdomain.google.com/you_are_on_the_internet' site/page that Google Chrome can use to check to see if it's captive or not. If it's captive, enable soft-fail. If internet access is available, set to hard-fail.
Websites these days are complex, with many (digital) moving parts - the database server(s), the static image server(s), dynamic response server(s), gateway server, probably a memcache server or something similar. If any one of those goes down, the site is unusable. Why then, should the OCSP server going down be considered any differently? Is a black-hat rented bot-net running a DDoS going to care if it's the main gateway server or the OCSP server?
But let's say we do consider disabled OCSP servers to be a client-side issue. Google could query and cache the OCSP server status, either with OCSP stapling or via some side-channel they build into Google Chrome.
The combination of both would allow hard-fail to be an option in Google Chrome.
Everyone does soft-failHowever what I meant to suggest is a third option. Something like hard-fail with a latch. The client should opt to fail but give the user the choice to proceed.
This would seem more desirable than the current soft-fail implementations when seem to be entirely silent to the end user.
You would see a huge influx of bugzilla entries of "Firefox is broken" if hard fail was the default.
edit: the checkbox in the validation subdialog (ocsp.xul) is tied to security.OCSP.require, which is set here with a default of false in the Firefox source: http://dxr.mozilla.org/mozilla-central/source/netwerk/base/p...
I think some extension or some other thing changed them for me. I don't remember ever opening the OCSP dialog until now :/
Edit: I get it, I missed that for sites where the key has been changed the stolen key no longer allows such eavesdropping. Thank you to yuhong for helping point this out rather than just laughing at my ignorance while pushing me down the page.
X.509 certificates bind a public key and a human recognizable string (a "common name") together to create a verifiable digital identity. Over-simplified, X.509 is about solving the "I'm Spartacus" problem.
CRLs solve the "He was Spartacus" problem. I agree with the broad conclusion that CRLs aren't effective for human trust, but they are perfectly reasonable for machine trust.
Why didn't the author mention Kerberos? The default lifetime of a Kerberos ticket is designed around humans: roughly the length of a work shift in front of a computer terminal.
final edit: meta-moderation is hard
Name != Identity
It's nearly impossible to have a meaningful English conversation about these problems without getting that straight.