A description and set of rules for the ordered exchange of structured information designed with the goal of protecting the security of the system.

learn more… | top users | synonyms

116
votes
3answers
87k views

What's the difference between SSL, TLS, and HTTPS?

I get confused with the terms in this area. What is SSL, TLS, and HTTPS? What are the differences between them?
79
votes
8answers
14k views

What would one need to do in order to hijack a satellite?

I realise this borders on sci-fi, but there's been some interesting demonstrations regarding security of various satellites. What would be required to hack a satellite (in general terms, any hack ...
39
votes
3answers
4k views

Is Git crowdsourcing cryptographic attacks?

A strong cryptographic hash makes collisions unlikely. Many cryptographic protocols build on that fact. But Git is using SHA-1 hashes as object identifiers. So there are a lot of already computed ...
26
votes
3answers
20k 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, ...
23
votes
7answers
36k views

What is the difference in security between a VPN- and a SSL-connection?

I would like to design a client-server application where the server is placed on Internet. I assume that I could set up the client-server connection using VPN (is it using IPSec?) or using a SSL ...
23
votes
3answers
2k views

How does Convergence (CA replacement) prevent its notaries from being MITM'd as well?

I have been looking into Convergence and how it works, but I cant figure out how it is effective against a MITM attack that happens near the target system. My understanding is that Convergence works ...
23
votes
4answers
6k views

Preventing artificial latency or “Lag Hacking” in multiplayer games

There is an attack that some people have dubbed "lag hacking", and its gaining popularity in multiplayer games. There are at-least two ways of creating artificial latency. One method of introducing ...
20
votes
2answers
770 views

Aviation security - Lessons to learn from PlaneSploit

A somewhat related question has already been asked (What would one need to do in order to hijack a satellite?), only at a more abstract level. Now we have a presentation by Hugo Teso from n.runs AG ...
19
votes
1answer
4k views

Is there a standard for printing a public key as a barcode?

Is there a standard for storing a public key printed on paper? Say, I want to hand out business cards with my public key pre-printed on them at a key signing party to help build the web of trust. My ...
18
votes
3answers
4k views

Convergence - an SSL replacement?

Today, Moxie Marlinspike, a security researcher famous for his research on Android and SSL and related protocols (author of sslstrip/sslsniff), released "Convergence" which says is "an agile ...
15
votes
6answers
7k views

How to implement multi factor authentication using a token generator?

I'd like to implement multi factor authentication on a few projects. Now the first factor would be username and password, for the second factor I would like to use a token generator. These tokens ...
15
votes
2answers
7k views

The inner workings of iMessage security?

This is a very interesting article about the iMessage technology used in Apple's very popular communication devices. So far, there has not been much technical details released by Apple. Hopefully ...
12
votes
3answers
2k views

How are mobile telephony networks like LTE and HSPA encrypted?

How are mobile telephony networks like LTE (4G) and HSPA (3G) encrypted? between what parts is the communication encrypted? who has access to the keys? is symmetric or asymmetric encryption used? is ...
11
votes
1answer
1k views

Native rsync protocol security

Is the native rsync protocol (port 873) secure? Does it encrypt data or credentials? I'm planning on using rsync to store encrypted files in the cloud, I'm wondering whatever the password is ...
11
votes
1answer
5k views

What changed between TLS and DTLS

What did the DTLS (TLS over UDP) authors have to change so that it could run without TCP? Bonus points: Do any of the protocol difference affect the way it should be used, both in terms of interface ...
11
votes
3answers
823 views

Is off-the-record style encryption possible with email?

The instant messaging world has off-the-record encryption - which means you get authentication, encryption, and forward deniability. Key material is published after a session ends such that an ...
11
votes
1answer
2k views

SSL TLS renegotiation vulnerability - current situation in clients

Reading about the SSL renegotiation problem CVE-2009-3555 one knows that servers supporting old type of renegotiation are vulnerable to data injection. We also have tools to test them (openssl ...
10
votes
2answers
422 views

How do new security and cryptography techniques/protocols avoid the chicken-and-egg problem?

. . .better solutions have been proposed and will be worth considering once they have withstood the test of time (i.e. “5 to 10 years in the field, and not broken yet”). -From Thomas Pornin's ...
9
votes
4answers
10k views

How do the processes for digital certificates, signatures and ssl work?

I have been trying to understand how ssl works. Instead of Alice and Bob, lets consider client and server communication. Server has a digital certificate acquired from a CA. It also has public and ...
8
votes
3answers
3k views

What common products use Public-key cryptography?

I want know what common use products are there that use public key/private key cryptography?
8
votes
4answers
2k views

extract from pcap all protocols found

I have some pcap files, and i would like just to get a list of protocols that are present on that pcap file. I would like it in a batch mode, not using wireshark I think tshark is able to do it, but ...
8
votes
1answer
1k views

Why would HTTP client only send authentication headers once an unauthenticated request was rejected?

The default usage of HttpClient and HttpWebRequest .NET classes is setting Credentials property and then asking the class instance to perform an HTTP request. If the target requres Basic authorization ...
8
votes
2answers
2k views

How does Diaspora work?

I hear all this hype about Diaspora being decentralized, but the only information I can find on their official website and the Wikipedia article is that several people can run Diaspora servers. The ...
8
votes
1answer
791 views

What were the specific security flaws with OAuth 1.0? How are they being addressed in 2.0?

I read an article documenting Twitter abruptly pulling its OAuth support back in April 2009. The article said it wouldn't specify the hole for security reasons, but mentioned "social engineering" is ...
7
votes
3answers
376 views

How do I test and secure ASN.1 Parsers?

As far as I can tell, .NET doesn't have an ASN.1 parser for reading or writing data built in the framework. This means that any code that creates or verifies ASN.1 data is using a 3rd party library ...
6
votes
4answers
2k views

Is this type of ARP poisoning attack possible?

I am wondering if it is possible to paralyze a network by sending out a bunch of fake ARP response packets. Some basis: I recently read a moderately detailed description of how ARP and ARP poisoning ...
6
votes
2answers
7k views

The new CCMP attack against WPA/WPA2 PSK

The use of Counter Mode with Cipher Block Chaining Message Authentication Code Protocol (CCMP) for WPA/WPA2 PSK is being attacked. This is a trivial attack (offline brute force) against the initial ...
6
votes
3answers
855 views

How do I identify an unknown port/protocol that my IDS picks up?

Googling a port and protocol leads to a terse description at best, and a linkfarm in the average case. Most protocols on assorted, unknown high ports contain little or no plaintext, and often if the ...
6
votes
4answers
399 views

Are there a standard method(s) for me to give someone else read-only access to my data?

Are there a standard method(s) for me to give someone else read-only access to my data? There are several situations where I may want to give a few people read-only access to some data, but I would ...
6
votes
3answers
673 views

Patent free symmetric-only key exchange protocols?

I am working with a networked embedded device with AES-128 and no public key cryptography (1KB RAM, 8KB flash). At install, the device is pre-loaded with a longterm AES-128 key known also to the ...
6
votes
1answer
2k views

What does chacha20-poly1305@openssh.com mean for me?

OpenSSH just introduced a new protocol, chacha20-poly1305@openssh.com, which combines the two algorithms from DJB: ChaCha20 and Poly1305-AES. It was inspired by a similar proposal for TLS, which ...
5
votes
5answers
3k views

How secure is using CRAM-MD5 for email authentication, when not using an SSL connection?

Background: My current server-provider tells me it's no problem to store the passwords in plain-text in the database, saying he has to do so because they use CRAM-MD5 for email authentication. My ...
5
votes
3answers
20k views

Four-way Handshake in WPA-Personal (WPA-PSK)

Can someone explain to me in what consists the Four-way Handshake in WPA-Personal (WPA with Pre-Shared Key), which informations are being sent between AP and client, how is it possible to find the AP ...
5
votes
2answers
1k views

Why is NIST removing & not updating TLS guidance? What is the replacement?

The document NIST Special Publication 800-52 Guidelines for the Selection and Use of Transport Layer Security (TLS) Implementations was retired without superseding it with a newer document. In ...
5
votes
1answer
568 views

How do you analyze an unknown network protocol?

Of course Wireshark can be used to sniff traffic - you can inspect each packet or chain of packets. But how would you do it smarter? Which tools do you use to identify behaviors or to automate the ...
5
votes
3answers
4k views

What makes the Blackberry device and network more secure?

One of Blackberry's strongest assets is the "network" that it uses. Can someone explain, or link to technical information that covers what this secure network is, and what it does better than the ...
5
votes
1answer
3k views

What block ciphers and algorithms are now safe? [closed]

I work for a large non-US based international organisation. Regarding the recent leaks about the NSA breaking most encryption on the internet, we now know the US and UK governments are actively ...
4
votes
2answers
450 views

In a browser web server communication, who decides which encryption protocol to use [duplicate]

My IE browser has SSLv3.0, TLS 1.0,1.1 and 1.2 has enabled in the advanced settings. And (I was informed by my server admin) my web server can encrypt data in SSLv3.0 and TLS 1.0 Now which system ...
4
votes
3answers
3k views

Safe to expose Active Directory via LDAPS externally?

We currently access Active Directory via LDAPS internally for authentication and user data retrieval. Is it common, or safe, to expose this publicly over LDAPs? Addendum 1: Our business case, ...
4
votes
4answers
551 views

Does TCP/IP expose critical infrastructure to added risk?

Background: I just attended a talk on the security of critical infrastructure. The speaker spoke a bit on how adding the TCP/IP protocol to functions usually taken care of by dedicated protocols open ...
4
votes
3answers
165 views

I want to have the security of my crypto code checked, how should I go about doing so?

Specifically part of my system stores encrypted information in a database. I wrote the code that actually does the encrypting/decrypting using an existing cipher. How should I go about making sure ...
4
votes
2answers
179 views

What happens if a pro-censor ISP has Telex key(s)?

I've been watching more and more people jump on the idea of Telex as a way to prevent internet censorship (e.g. http://www.technologyreview.com/communications/38207/ -- not my comments at the bottom ...
4
votes
2answers
880 views

IPsec - when to use AH only?

As far as I know, AH only covers integrity and authentication. So, suppose that an intermediate router receives the packet with AH and not ESP. Then, can't the router open its content (<- and ...
4
votes
1answer
133 views

Are the SSL Digital Security Certificates based on Kerberos Network Security Protocol

I just want to know if digital certificates use the kerberos session key algorithm.
4
votes
1answer
239 views

Two generals' agreement

I am trying to figure an agreement protocol on an unreliable channel. Basically two parties (A and B) have to agree to do something, so it's the two generals' problem. Since there is no bullet-proof ...
4
votes
3answers
384 views

Are there any serious problems with this technique for generating symmetric keys?

I'm using a technique borrowed out of a book by Bruce Schneier and Niels Ferguson called Practical Cryptography. Basically, it boils down to this: Bob does this: pubk_A = Alice's public key ...
4
votes
1answer
247 views

Can wildcard certificates hide/obscure the hostname in a TLS connection?

I'm trying to increase security for my cloud-based / multi-tenant environment. I'm considering having clients access an obscure URL such as GUID.myCloud.com. I will then respond to that guid-based ...
4
votes
1answer
3k views

Is L2TP as secure as IPSEC for VPNs?

Is it as secure to use L2TP for VPN access, rather than IPSEC? Am I introducing any risks by using L2TP?
3
votes
4answers
282 views

What's the need of multiple implementations of SSL/TLS? [closed]

I've been reading about SSL/TLS and I was surprised when I saw the amount SSL/TLS implementations that exist. wikipedia. So, is there really a need for all these different implementations? Wouldn't ...
3
votes
4answers
870 views

Can we prevent a man-in-the-middle attack with symmetric-key cryptography?

Suppose that Alice signs the message M = "I love security" and then encrypts it with Bob's public key before sending it to Bob. As well known, Bob can decrypt this to obtain the signed message and ...