Is there any technical security reason not to buy the cheapest SSL certificate you can find?

Question

While shopping for a basic SSL cert for my blog, I found that many of the more well-known Certificate Authorities have an entry-level certificate (with less stringent validation of the purchaser's identity) for approximately $120 and up. But then I found that Network Solutions offers one of these lower-end certs for $29.99 (12 hours ago it was $12.95) with a 4-year contract.

Is there any technical security reason that I should be aware of that could make me regret buying the lowest-end certificate? They all promise things like 99% browser recognition, etc. I'm not asking this question on SE for comparison of things like the CA's quality of support (or lack thereof) or anything like that. I want to know if there is any cryptographic or PKI reason so avoid a cert which costs so little. It, like others, says that it offers "up to 256 bit encryption".

Answer 1

For the purposes of this discussion there are only a couple differences between web signing certificates:

1. Extended vs standard validation (green bar).
2. Number of bits in a certificate request (1024/2048/4096).
3. Certificate chain.

It is easier to set up certificates with a shorter trust chain but there are inexpensive certs out there with a direct or only one level deep chain. You can also get the larger 2048 and 4096 bit certs inexpensively.

As long as you don't need the extended validation there is really no reason to go with the more expensive certificates.

There is one specific benefit that going with a larger vendor provides - the more mainline the vendor, the less likely they are to have their trust revoked in the event of a breach.
For example, DigiNotar is a smaller vendor that was unfortunate enough to have their trust revoked in September 2011.

Answer 2

Good stuff in other answers, let me add some remarks about proper CA behaviour.

If the CA has an history

• of lack of security policy enforcement,
• of violation of "browser approved CA" agreement,
• of signing of non DNS names using their official root certificate (like IP addresses, or non existent DNS names f.ex. bosscomputer.private),
• of lack of transparency about its behaviour and its resellers,

and the end user (like me) inspects your certificate, and knows about this, that might reflect badly on you. Especially any CA that is a subdivision of a company also in the business of connexion interception.

When I see USERtrust or COMODO or Verisign in a certificate chain, I am not positively impressed.

Answer 3

From a technical standpoint, the only thing that matters is browser recognition. And all of the trusted authorities have very nearly 100% coverage.

I could say more, but to avoid duplicating effort here's a nearly-identical question with a lot of well-reasoned responses: Are all SSL Certificates equal?

Answer 4

In light of the latest NSA revelations, I'd say the entire concept of commercial Root CAs is fundamentally flawed and you should just buy from the cheapest CA whose root certificate is installed in browser and operating system trust chains.

In practice, we need multiply-rooted certificate trust chains instead of the current singly-rooted trust chains. That way, instead of ignoring the real power of governments to "coerce" commerical providers - you'd simply get your certificate signed by multiple (preferably antagonistic) governments. For example, have your Bronies vs Juggalos cage match website signed by USA, Russia, China, Iceland and Brazil. Which might cost more but would really reduce the likelihood of collusion.

Answer 5

For a domain validation certificate, the only thing that matters is whether browsers accept the certificate as trusted. So, take the cheapest cert that is trusted by all browsers (or all browsers you care about). There is no significant cryptographic reason to prefer one supplier over another.

(You will of course have to pay more for an extended validation certificate, but that's an entirely different class of certificate. I think you already know that.)

Answer 6

No matter which CA you go with, your users' assurance that they're actually communicating with your site and not an attacker is only as good as the worst CA their browser trusts - an attacker who wants to forge a certificate can shop for a CA with bad practices. So I don't see any plausible argument that your choice of CA impacts your site's security, unless you choose a CA that generates private keys for you rather than signing a key you provide, or that disallows large key sizes.

Other than that, as others have said, it's probably a good idea to avoid CA's whose mix of bad practices and small size makes it plausible that their trust might be revoked by one or more browsers, since this would impact the accessibility (and public perception) of your site.

Answer 7

You will soon be able to You can get certificates for the low cost of zero € with Let's Encrypt.

They are technically as good as any other (non-extended validation, basically without the green bar on your browsers), the main point being the capacity of browsers to recognize it as trusted (they will are).

The only drawback is that there is a call-back from Lets' Encrypt to your site or DNS, which makes the certificate generation painful (if not impossible) for internal (non-Internet) sites.

Answer 8

In general the two things which you probably can pass on are the EV (since that is just the green bar gimmick) and also SGC does not really provide any real benefit today (since it only applies to browsers from the days of IE5 and before)

This site provides a good overview of why to avoid SGC: http://www.sslshopper.com/article-say-no-to-sgc-ssl-certificates.html

Answer 9

Ignoring the technical aspects of certificate encryption, the issue to consider is trust and reputation. If you are only concerned about encryption of the traffic, then you can use a simple self signed certificate. On the other hand, if what you want to achieve is to provide a level of trust that you or your site really is who/what it claims to be, then you need a certificate from a certificate authority which people trust.

The CA achieves this level of trust through vetting of the people they sell certificates to. Many of the cheaper certificate providers achieve their lower prices by reducing their operational overheads and this is often done by having less rigorous vetting processes.

The question should not be "Who is the cheapest certificate provider", but rather "Which certificate provider has the necessary reputation and level of trust which users or potential users of my service will accept".

P.S. Unfortunately, to some extent, the whole model is broken anyway. Few users even check to see who the CA is that issued the certificate and have little knowledge or understanding of the chain of authority involved.

Answer 10

From a pragmatic standpoint for a site with standard-type users, the only criteria that matters for an SSL certificate is "is it supported by the browsers that my users will use to access the site". As long as it is, you're fine with it being as cheap as possible.

A while back a potential differentiator was whether the certificate was EV SSL or not but to be honest I've not seen great user awareness of that, so unlikely to be worth the money.

Answer 11

SSL certificate is used for two purposes.

• One is securing online transactions and private information which is transmitted between a web browser and a web server.
• Second is Trust, SSL is used for increase customer confidence. SSL proves secure session of your website, it means your customer trust on your website.

Each certificate has own validation process and following this process certificate authority validates your business reliability and send a certificate for your website.

A basic cheap SSL certificate only validates your domain authority and authenticated using the approver email verification system. Approver can easily get this certificate in just minutes with a generic email address.

OV and EV SSL certificates plugged with customer’s trust and through its strict authentication process, it gives the highest level of trust. EV SSL validates manifold components of identifying your domain and business information. It follows manual verification process and during this process system fails to verify or system defendants your business for potential false action then your order may be lined up for manual review.

The main difference in trust factor and brand reputation, while your customers see the green address bar in your browser then they feel more secure and encourage to make transactions. Otherwise, some differences between other features like encryption, browser compatibility, key length, mobile supports, etc.

Otherwise, certificates warranty explains differences. Certificate authorities provide extended warranty ($1K to $1.75M) against mis-issuance of an SSL certificate which explains the worth of your investment for website security.

While we focus on the price of a certificate, it doesn't matter where to buy your certificate – certificate authority or an authorized reseller. Authorized reseller offers same SSL products, same security features, better support at reasonably priced.

Jason Parm is affiliated with SSL2BUY (Global SSL Reseller)

Answer 12

It's a bit late but for other like me searching the web to find what SSL Certificate to buy and here is the outcome of my research:

On the technical side the expensive SSL Certificates offer dynamic seal which means a dynamic image displayed on a website that shows the current time and date of when the web page was loaded which indicates that the seal is valid for the domain it is installed on and is current and not expired. When the image is clicked, it will display information from the Certificate Authority about the website's profile which validates the web site's legitimacy. This will give visitors of the website increased confidence in the site's security.

A Static Seal is simply an static graphic image that can be placed on the website to indicate where the digital certificate was obtained from, however there is no click-through validation of the website and the image does not show the current time and date.

Also if you are buying more expensive SSL you will get more money in fraud warranty for your visitors, but only in case if the Authority issued a certificate to a fraudster and a visitor lost their money believing the website is legit. If you are not a fraudster there is no reason you should go for expensive certificate unless you want to show green address bar and increase the confidence in your visitors.

Technically there is no other difference

There is 3 main types of SSL Certificates

Single Domain

• Secures both www and non-www versions of your domain
• Examples: RapidSSL, Comodo Esential etc.

Wildcard

• Secures all subdomains for a single domain including www and non-www versions
• Examples Comodo Wildcard SSL, RapidSSL Wildcard etc.

Multi Domain

• Most of Certificate Authorities give 3-5 domains with their basic price plan
• You need to pay per additional domain. Typically arround $15-$20/year per domain
• Examples Comodo Positive Multi Domain SSL

Also 3 types of domain verification

In order to get your SSL Certificate issued the Certificate Authority has to verify that you are who you said you are when requested the certificate with them. The following are 3 of the verification processes you have to go through when getting an SSL

1. Domain Validation

You have to validate your domain. Typically this happens through URL link sent to one of the emails on your domain or with file upload to your server. By far this is the quickest, simplest and cheapest SSL. The warranty against fraud with this type of validation is up to $10,000.

2. Organisation Validation

You have to provide supporting documentation about your organisation in order to get one of this certificates. This process is a bit slower and can take up to couple of days. This type of SSL security is required for large e-commerce websites or organisations that store sensitive user data. Typically this certificates offer dynamic site seal and offer higher warranty of up to $1,500,000 depending on the issuer.

3. Extended Validation

This are most trusted Certificates and will turn the address bar in your browser in green containing the name of your organisation. By far the slowest validation process of up to a week, depending on the external body verifying your details. You will have to provide the SSL Authority supporting documents like company incorporation etc. and they will pass this onto third party to verify it's validity. Once this process is successfully complete you will have the highest trust and warranty of up to $2,000,000 depending on the issuer.

What certificate to buy

This is all up to you. There is plenty of Certificate Authorities offering a lot for each need. For me the leading point is do not spend unless you have to. Basic SSL Certificate will do pretty much the same as the most expensive SSL on the market.

Here is some usefull links

Certificate Authorities

• Comodo
• RapidSSL
• Thawte
• Symantec

Some of the cheapest resellers

• Hostedo
• Namecheap
• Go Get SSL

Answer 13

DV should be enough for most browsers

The article "Understanding risks and avoiding FUD" on Unmitigated Risk mentions three assurance levels of certificates signed by a certificate authority. To these three I will add two lower assurance levels possible without a CA-signed certificate. This makes a total of five tiers of HTTP security to consider:

1. No TLS (http:)
2. TLS with a certificate that is self-signed or from an otherwise unknown issuer
3. TLS with domain-validated (DV) certificate from a known issuer (organization not part of certificate)
4. TLS with organization-validated (OV) certificate from a known issuer (organization name in certificate)
5. TLS with Extended Validation certificate from a known EV issuer (organization name and address in certificate)

Certificates that you buy from a commercial CA will be 3, 4, or 5. Most web browsers allow all but 2 with no interstitial warning, even though 2 is better than 1 in resistance to passive attacks. The commonly expressed rationale is that an https: URI with an unknown CA gives a false sense of security, particularly against a man in the middle, while an http: URI gives a true sense of insecurity.

But DV may scare Comodo Dragon users

But a minority of users use a web browser that warns on 3 as well. When a user of Comodo Dragon visits an HTTPS site that uses a DV certificate, it displays a different lock icon with a warning triangle, which resembles the "mixed passive content" icon. It also displays an interstitial warning screen before viewing the site. This warning resembles what browsers display for a self-signed certificate, and its text begins as follows:

It may not be safe to exchange information with this site

The security (or SSL) certificate for this website indicates that the organization operating it may not have undergone trusted third-party validation that it is a legitimate business.

This is intended to stop attackers who register a domain bankofamerrica.example for "Banko Famer Rica", put up colorably legit content about Costa Rica, obtain a DV certificate for that domain, and then change it to a site that impersonates Bank of America. It's also intended to stop an attacker who compromises a domain, adds a subdomain that he controls, and obtains a DV certificate for that subdomain. One such case happened in December 2015 once the no-charge DV CA Let's Encrypt went live. But it's been seen to display this message even for Facebook.

To not scare users of Dragon, you need to avoid DV certificates. But you don't need to buy an EV certificate. Just make a list of CAs willing to sell your organization an OV certificate whose root certificate is in all major browsers. Then there's no technical security reason not to buy the cheapest one.

If you're operating your blog as an individual, you may not qualify for an OV certificate from any CA. In this case, you just have to live with the warning in Dragon, and you can just go with a cheap DV certificate like the one StartSSL, WoSign, or Let's Encrypt offers.

Answer 14

I would like to add that while the technology is the same with 256 bit encryption, you are also paying for the following factors:

Level of validation - this is the amount of checks that the issuer will do to verify your company or website

Number of domains - how many domains this certificate will be valid for

Trust level - as members mentioned above, you can pay for different types of validation with are "trusted" more by users, thus the difference in pricing