-1
votes
4answers
153 views

Secure communication between server and client [duplicate]

I'm writing some security software, and don't want anyone to be able to intercept data as its passed from client->server, and server->client. The best way to do this is over HTTPS via SSL. However, ...
0
votes
2answers
210 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
95 views

SSL/TLS Question [closed]

I am currently working on my SSL/TLS assignment and I got a question to ask. What is the use of a login password since it is not needed for establishing secret communication between your computer and ...
5
votes
2answers
1k views

1024-bit DHE vs 2048-bit RSA

Currently with apache/mod_ssl, if DHE is enabled then a 1024-bit ephemeral key will be used. I found the following quote in Adam Langley's blog: Ideally the DH group would match or exceed the RSA ...
1
vote
1answer
263 views

OpenSSL DH modp size

If OpenSSL is configured to use a DH for key exchange, e.g. TLS_DHE_RSA_WITH_AES_128_CBC_SHA, where does it take the size for modp (or even modp itself) from? The following is a screenshot from ...
5
votes
1answer
196 views

Any not totally insecure browser vulnerable to BEAST?

People still worry about BEAST quite a lot when configuring web servers to the point of preferring RC4 over AES-CBC. But most browsers mitigate BEAST even while using TLS 1.0. Is there a browser ...
10
votes
4answers
498 views

What was SSL 1.0?

What was SSL 1.0? SSL 2.0 and 3.0 are well-known and well-documented. But what did the SSL 1.0 protocol look like? Wikipedia says there was a SSL 1.0 but doesn't say anything about how it worked. ...
2
votes
2answers
433 views

Please help verify my understanding of Domain Validation (DV) SSL Certificate

This is what I understand so far from reading various knowledgebase and article about DV SSL. Can anyone please help clarify if any of these is wrong? DV SSL (and SSL certificate in general) is only ...
4
votes
1answer
752 views

Whats the best custom compression method to use when I have SSL?

Suppose I have an application which does encryption using SSL and provided you cannot control what cipher suite is being negotiated, and assuming that I have some custom compression over the data ...
3
votes
2answers
290 views

Should I customize my Root CA's thumbprint/fingerprint? (SHA1 or MD5)

My goal is to make a certificate's thumbprint "easier" to verify, and not reduce security in doing so. Given that the RSA-based Bitcoin technology has a concept called a "Vanity address" where the ...
2
votes
2answers
1k views

Checking if TLS 1.1 and 1.2 implementation in a webserver is upto standards

I am testing a webserver[proprietary] which offers SSL support and they say it supports TLS 1.1 and 1.2 which i have verified by firing requests from IE with only the target protocol enabled . ...
8
votes
1answer
322 views

Build a secure channel without SSL/TLS

I'm looking at possible options to build a secure channel between multiple embedded devices with limited cryptography capabilities and an HTTP server (It could be some sort of web service). 1. ...
12
votes
3answers
889 views

Multi-tenancy, SSL Certificates, and Subject Alternative Name

The X509 specification allows a CA to issue a single certificate for multiple hostnames, by using the "Subject Alternative Name" extension. From the spec: The subject alternative name ...
1
vote
1answer
104 views

SSL Communication and Proxy

Let us say that I have a client and a server communicating using SSL. If a hacker sets up a proxy between the client and the server, will he be able to decrypt the data which is being sent?
4
votes
3answers
226 views

What SSL options should not be used?

What SSL options should be avoided, due to recently discovered weaknesses? This might include symmetric algorithms, or MAC functions.
3
votes
4answers
494 views

Can an attacker reuse stolen SSL private key to recreate that domain on his server

Say my domain (https://example.com) SSL private key has been stolen and was not protected by a passphrase then. Can the attacker uses that key and certificate to host the same domain on different ...
0
votes
1answer
386 views

Is TLS secure when full eavesdropping on the network occurs? [duplicate]

Possible Duplicate: How is it possible that people observing an HTTPS connection being established wouldn’t know how to decrypt it? Alice connects to Bob's site via a TLS secured connection ...
2
votes
3answers
1k views

KDC(Key Distribution Center) vs Asymmetric Key Exchange

Today I was reading notes about cryptography and I came across a problem that exists in Symmetric Key encryption, which is how to share the secret key across the network. 1st Method : Make use of ...
5
votes
1answer
271 views

Most efficient key algorithm for a TLS server key?

Let's assume I want to setup a HTTPS service on a modern-but-no-so-speedy x86 server without any form of hardware cryptographic accelerator. Which key algorithm should I choose for the server key in ...
9
votes
2answers
1k views

Are there really functioning quantum computers?

I saw this video on youtube on quantum computing. It says that a company called dwavesys has already made commercially available quantum computer. I checked on the website and it exists. I thought ...
20
votes
2answers
2k views

Is HTTP compression safe?

The CRIME attack taught us that using compression can endanger confidentiality. In particular, it is dangerous to concatenate attacker-supplied data with sensitive secret data and then compress and ...
3
votes
1answer
118 views

CMC (RFC 5272) compatible CA server

I need a CA server or any tool that supports Certificate Management over CMS (CMC) format, described in RFC 5272 (RFC 2797). I need a possibility to generate different Full PKI requests and responses ...
3
votes
1answer
82 views

SSL Based Denial of Services due to Message Digest

On a very high level, its known that SSL/TLS uses message digests to verify the integrity of the messages sent. However, the question I have in mind is : How does SSL ensure a DoS does not happen ...
7
votes
3answers
414 views

How secure is HTTPS with weak ciphersuites?

Today I came across the website https://mtgox.com/, which claimed to be secure because of the Verisign certificate. I checked the certificate out of curiosity (it's the first thing they claim, let's ...
7
votes
4answers
3k views

HTTP Basic auth password storage more secure than Digest auth

If you are using SSL already, it appears Basic auth is the way to go since you can perform bcrypt with the password when you store it in the database, where as Digest auth only allows md5. As we know, ...
1
vote
1answer
2k views

What are the consequences of disabling ssl v2 and weak ciphers?

It is my understanding that IIS has ssl v2 enabled by default. Also, TLS 1.0, if enabled, allows for at least one known major vulnerability titled "beast attack". If the weak and vulnerable ciphers ...
20
votes
3answers
13k views

What is ECDHE-RSA?

What is the difference between ECDHE-RSA and DHE-RSA? I know that DHE-RSA is (in one sentence) Diffie Hellman signed using RSA keys. Where DH is used for forward secrecy and RSA guards against MITM, ...
10
votes
1answer
6k views

What is the actual value of a certificate fingerprint?

In a x509 digital certificate there is a "certificate fingerprint" section. It contains md5, sha1 and sha256. How are these obtained, and during the SSL connection, how are these values checked for?
5
votes
4answers
998 views

Does a CA need to have the same type of key as the certificates it is signing? RSA / Elliptic Curve (EC/ECDH/ECDSA)

I am making a CA that I hope to be able to sign RSA and Elliptic Curve-capable (EC) keys with. I was wondering if the best approach was: CA with RSA keys capable of signing RSA and EC CSRs CA with ...
5
votes
3answers
545 views

TLS Renegotiation Indication Extension vulnerability

I am trying to understand the TLS Renegotiation Indication Extension from the RFC. I can understand that it is related to the fact that the renegotiation is sent under the encrypted stream, but I ...
3
votes
1answer
1k views

how do extended validation X.509 certs work?

https://www.forumatic.com/ uses an extended validation cert. wikipedia.org's entry on extended validation certs says that a cert is known to be an extended validation cert if the OID in the ...
1
vote
3answers
7k views

What does these warnings mean on an SSL connection by firefox (only)

I am connecting to a secure site and firefox mentions about identity: Owner: This website does not supply ownership information Verified by: Not specified Technical Details: Connection ...
2
votes
1answer
453 views

Is SSL session based only? Is there a (formal) definition of an SSL connection?

In various docs on SSL there is a mention of connection. But from the context I am not sure if this means the underlying TCP connection or the SSL connection. I am thinking that there is no SSL ...
2
votes
1answer
169 views

Browsers and export regs. Is SGC still valid?

I was reading a rather "dated" book on SSL/TLS, which mentions about International Step Up certificates and Microsoft's Server Gated Certificates which were the way arround the US export rules for ...
3
votes
4answers
15k views

how safe is the 256 bit encryption used in bank transactions

Most of the banks use a 128 bit or 256 bit encryption. What does this mean? Does it mean that the keys used in ssl are 128 bit long or what? If they are the ssl key lengths then 128 bit rsa keys are ...
1
vote
1answer
100 views

valid intermediate certs not in browser

Say an X.509 cert is signed by an intermediate cert that's not in your browser. Maybe the root certificate is but not the intermediate cert. At that point it seems like a valid certification path ...
3
votes
2answers
170 views

self-signed certs that aren't the final certificates in the path

The X.509 spec makes frequent statements like this: (b) If certificate i is self-issued and it is not the final certificate in the path, skip this step for certificate i. How can you have ...
8
votes
2answers
487 views

X.509 certificate policies question

I asked another question about certificate policy mappings. This is a different issue. This is about Certificate Policies. To quote from the X.509 RFC: In an end entity certificate, these ...
2
votes
1answer
408 views

X.509 certificate policy mapping question

So I'm a little confused how X.509 certificate policy mappings work. So let's say the following depicts my cert chain: root CA ---> intermediary CA ---> client cert Would the root CA have a ...
1
vote
1answer
2k views

Explanation of SSL handshake with certificate

I've read a lot of articles. The client uses the information sent by the server to authenticate the server. If the server cannot be authenticated, the user is warned of the problem that an ...
4
votes
2answers
4k views

Confusing about Ephemeral Diffie-Hellman

1 Does Ephemeral Diffie-Hellman support authentication? Quote from www.rsa.com/products/bsafe/documentation/mesuite21html/dev_guide/group_EPH_DH.html Ephemeral Diffie-Hellman does NOT provide ...
0
votes
1answer
269 views

id-ce-cRLDistributionPoints ASN.1 / DER encoding question

I have a file - test.pem - with the following contents: -----BEGIN CERTIFICATE----- MBIwEKAOoAwwCqMIMAZhBEFCQ0Q= -----END CERTIFICATE----- openssl asn1parse -inform PEM -in test.pem -i returns the ...
2
votes
1answer
434 views

question about implicitly tags in ASN.1

From the X.509 RFC, in the "Implicitly Tagged Module" section: CRLDistributionPoints ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint DistributionPoint ::= SEQUENCE { distributionPoint [0] ...
3
votes
1answer
3k views

Recommended Cipher Suites for TLS 1.0, 1.1 and 1.2

There are a lot of cipher suites defined in the in the specifications itself of TLS 1.0, 1.1 and 1.2. And furthermore, there exist RFCs which add even more cipher suites to a specific version (e.g. ...
4
votes
1answer
693 views

X.509 algorithm identifier parameters vs. extension values

From the X.509 specs: AlgorithmIdentifier ::= SEQUENCE { algorithm OBJECT IDENTIFIER, parameters ANY DEFINED BY algorithm OPTIONAL } ...
3
votes
1answer
849 views

Why doesn't asn1parse parse all DER encoding strings?

I have a file - crl.txt - that contains the following: MDYwNKAyoDCGLmh0dHA6Ly93d3cyLnB1YmxpYy10cnVzdC5jb20vY3JsL2N0L2N0cm9vdC5jcmw= It's from one of the extensions in a particular X.509 cert. Why ...
3
votes
1answer
879 views

parsing the id-ce-keyUsage extension in X.509 certs

I'm trying to decode an X.509 certificate and have a question regarding the decoding of the extensions. In particular, the octet string corresponding to id-ce-keyUsage (OID 2.5.29.15) is as follows: ...
2
votes
3answers
244 views

Help with SSL teaching material

I am taking a course on security next month. As the concepts of SSL/TSL are bit hard. I am looking for a nice way of presenting it to my students. They are Compsci undergrads. It would be nice to ...
5
votes
2answers
303 views

System for Mutual authenticaion and confidentiality

I am looking for a protocol where there needs to be mutual authentication between client and server. For example server should connect to a particular client only. That is client should authenticate ...
20
votes
3answers
7k views

Which SSL/TLS ciphers can be considered secure?

The OpenSSL website provides a long list of different ciphers available for SSL and TLS. My question is, which of those ciphers can be considered secure nowadays. I am especially interested in HTTPS, ...