The tag has no wiki summary.

learn more… | top users | synonyms

30
votes
1answer
7k views

TLS: RC4 or not RC4?

I was reading another interesting article by Matthew Green today, saying that if you're using RC4 as your primary ciphersuite in SSL/TLS, now would be a great time to stop As far as I'm aware ...
28
votes
1answer
3k views

How to describe RC4 'bias' to non-tech people

I'm looking for the 'plain English' version of 'bias' as used in the context of the RC4 weakness. I know that RC4 generates a string of psuedorandom bits over, for instance, http(s) traffic. If you ...
16
votes
4answers
15k views

Remove RC4 from SSL/TLS ciphers in Chromium

Recently I started to live without RC4 within my Firefox session. Discussion about it can be found here. While it is quite easy in Firefox (Enter about:config and then rc4), I found no possibility to ...
14
votes
3answers
822 views

Should I worry if my credit card payment processor's server allows only weak SSL cipher suites?

I tested their server using https://www.ssllabs.com/ssltest/ and, apart from the disappointing "B" rating (it handles financial transactions, after all), the server only allows the following two RC4 ...
11
votes
3answers
8k views

Can someone explain a little better what exactly is accomplished by generation of DH parameters?

I'm setting up a node.js server: https.createServer({ ... ciphers: 'ECDHE-RSA-AES128-SHA256:AES128-GCM-SHA256:RC4:HIGH:!MD5:!aNULL:!EDH', honorCipherOrder: true }, app).listen(443); ...
9
votes
2answers
568 views

RC4 bias protection with padding in TLS

On the answer to my previous question about RC4 vulnerabilities in TLS, Thomas Pornin gave a great answer, in which he said: One way to "fix" RC4, which has been suggested many times, is to drop ...
6
votes
1answer
7k views

Are there any known vulnerabilities in PPTP VPNs when configured properly?

PPTP is the only VPN protocol supported by some devices (for example, the Asus RT-AC66U WiFi router). If PPTP is configured to only use the most secure options, does its use present any security ...
6
votes
2answers
481 views

Implications of having a service account in AD use RC4 rather than AES for Kerberos?

Bear with me, I know this is sloppy, but here is the back story: We have a partner that uses Jira and is using spnego with a custom auth back-end that expects certain group membership in the token. ...
4
votes
2answers
442 views

Why do the banks all use weaker TLS suites? [closed]

I've been checking out various TLS certificates lately and noticed that most of the banks seem to have the following two issues: 1) They do not offer perfect forward secrecy 2) They are still using ...
4
votes
1answer
702 views

PFS on nginx: only RC4 gets used (TLS_ECDHE_RSA_WITH_RC4_128_SHA)

I'm trying to configure my webserver for perfect forward secrecy. I'm using ssl_ciphers ...
3
votes
1answer
1k views

Prevent BEAST attack without RC4 cipher suites

It is common practice to prevent the BEAST attack using the following ciphers in Apache SSL configuration: SSLCipherSuite RC4-SHA:HIGH:!ADH Unfortunately, RC4 has been found to be flawed and it is ...
3
votes
1answer
258 views

Are all cipher suites with rc4 in them intrinsically flawed?

I've been wondering lately if RC4 is so flawed in all its forms, why is it that it is still being supported by all major browsers per default? Why does the typical chrome browser prefer ...
3
votes
1answer
10k views

How does DHE-RSA-AES256-SHA compare to RC4 as the Cipher for SSL?

I read a lot of issue [1] currently stating that RC4 is broken and is at risk. I just checked my web server (nginx) and it is using the default settings, which is DHE-RSA-AES256-SHA How does this ...
2
votes
3answers
349 views

Does it make sense to keep RC4?

I know that the RC4 cipher when used with SSL is vulnerable to certain attacks, which in the worst case scenario could result in authentication tokens being stolen. But RC4 is also recommended as a ...
2
votes
1answer
59 views

SSL Mixed Scripting Vulnerabilities and XOR Attacks

Given that RC4 is a stream cipher (I'm pretty sure the details of its inner workings don't matter for the sake of this argument) and the existence of Mixed Scripting / Mixed Display (web applications ...
2
votes
2answers
110 views

What is the impact of removing TLS_RSA_WITH_RC4_128_SHA from my server's cipher suite?

I run a website that supports many clients via webservices. I'm setting up some new certificates and load balancers and when doing ssllabs's server test, it's flagging all my ciphers as OK except ...
2
votes
1answer
455 views

How strong is PDF security/encryption?

I want to securely convey a PDF document containing sensitive information from my system to another system. The latter is operated by a different person, whom I trust. However, this person does not ...
2
votes
0answers
62 views

For use with RC4 how do I combine a reused key and an initialization vector

I am an a-level student writing an encryption program using an rc4 implementation I have written myself. I have the basic algorithm coded correctly (and I have checked that some ciphertext for a given ...
1
vote
2answers
1k views

Clients breaking after avoiding RC4-MD5

As per http://projects.webappsec.org/w/page/13246945/Insufficient%20Transport%20Layer%20Protection , we have been recommended to stop using RC4-MD5. The clients supported by our Application are IE ...
0
votes
3answers
85 views

Disadvantages of disabling RC4 in SSL/TLS [on hold]

Other than requiring more server resources, are there any disadvantages of disabling RC4 from being using by an Apache webserver? My primary concern is preventing access from older browsers.
0
votes
2answers
548 views

Google's usage of RC4

I was reading about Google's usage of RC4 and an answer on stackexchange website stated the following: I know Google uses RC4 for most of its services, and this is the reason one shouldn't keep ...
0
votes
2answers
125 views

RC4 support in SSL configuration

GitHub recently improved its SSL setup by removing RC4 support: To keep GitHub as secure as possible for every user, we will remove RC4 support in our SSL configuration on github.com and in the ...