Questions tagged [protocols]

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

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What are non-standard ports and protocols [closed]

I am new to the security field and reading about how to check if an application is secure. One of the checks involves finding out if the app uses non-standard security ports and protocols. However, ...
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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 link farm in the average case. Most protocols on assorted, unknown high ports contain little or no plain text, and often if ...
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difference between public key and host key and security of host key

In SSH, what is the difference between host key and public key. Public key I believe that is part of private/public key pair, so, that anything sent by server(encrypted using private) can be ...
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How does the SSL connection protocol work with self-signed certificate? [duplicate]

I'm using the self-signed certificate, but I don't know how this protocol works. I connect two apps with a socket SSL and it works fine. The server is a Python app and the client is an Android app. I ...
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How can I implement a secure download area on a website which requires an electronic signature?

For quality management purposes, the company I work for would like a system which requires a client to read through a disclaimer and then provide an electronic signature, acknowledging said disclaimer,...
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What are the security implications of enabling a SNI-hole on a web server?

A web server (let's say Apache 2.4) implements SNI. It is configured with a 4096 bit SHA384-signed Wildcard Certificate (*.land.org) with a Subject Alternative Name (land.org). The Certificate ...
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WireGuard VPN: how safe is it for production in its current state?

In our project we had to build a VPN to get through to computers residing behind NAT. I never did it before. While looking for suitable software I came across WireGuard which claimed to be very simple....
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Has anyone had a look at DIME, the new Darkmail infrastructure, yet?

Background. In 2013, Lavabit and Silent Circle formed the Dark Mail Technical Alliance and launched the Darkmail project to create the Dark Internet Mail Environment (DIME) – a new mail architecture ...
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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 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 (...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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What are the security benefits or risks of HTTP/2?

Since HTTP/2 is starting to get adopted by more and more sites everyday. Are there any security benefits or known risks regarding HTTP/2?
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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?
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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 ...
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What is the serious security flaw with this authentication protocol?

I've been asked to solve this security problem, as an exercise, but I have some difficulties. Some notation: C1 means Computer1 S1 means Server1, TA means Trusted Autentication system, X -> Y | Z ...
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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 ...
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4answers
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Best way to push data to a client without being blocked by firewall

I'm asking this question here since I think people on this forum probably have the best knowledge of firewalls and routers. Say I'm designing a multi-player game and I want to push data to the client ...
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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 ...
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Minimum set of TLS features for an embedded device

I am reviewing the security of an embedded system, specifically how it uses the TLS or DTLS protocol to communicate securely. The system implements as few features of the protocol as it can get away ...
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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 that'...
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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 ...
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MQTT over TLS using RabbitMQ

We want to use RabbitMQ over TLS for our mqtt messaging, so we did some testing and managed to get it working over port 8883 using this configuration guide and we need to connect on a url that starts ...
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Biometric device instead of password - signature security

Lets assume that there is a bio-metric algorithm for user authentication which compares fingerprints with a user's signature saved in a database (comparing function is not important here). Next, there ...
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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 ...
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Why is the deprecated SSL 2.0 protocol considered insecure and how can it be exploited?

I am making a presentation to the class about "SSL 2.0 deprecated protocol" and I really have no idea how this exploit is used or how the attacker can use this vul. I understand the impact of this vul,...
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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 ...
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Is it possible to have a protocol that sits on top of TCP/IP that encrypts packets?

I was wondering if it is possible to make a new protocol which sits on top of TCP/IP and encrypts the packet which is going to be sent. One of the issues I can see is the metadata being available ...
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How does ndpi actually detect the HTTP protocol?

I have been digging the ndpi codebase and trying to understand how its actually detecting the HTTP protocol. What I found so far is that they are searching the request type in the payload and if not ...
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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 ...
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Secure information exchange between web applications using browser redirection

We're implementing a web application (US) that needs to exchange sensitive information with a third-party web application (THEM). The way we'd like it to work is that an end user clicks a hyperlink, ...
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Why should an IKE responder change the cookie secret 'frequently'?

IKEv2 has the concept of a COOKIE mode, to attempt to prevent state exhaustion from floods of initiation requests from non-existent IP addresses: Two expected attacks against IKE are state and CPU ...
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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.
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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 entropy ...
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What to do if you still have SMBv1 running on your network?

I was looking into the network traffic at our company while preforming a security audit and I found that we still have a server running SMBv1 on the network. The server is a Windows 2003 Domain ...
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Which are the most important RFCs when learning security? [closed]

I was reading some security related blogs and write ups in internet and I started going for the RFCs instead, but they are huge, therefore impossible to learn all of them. I see those below as very ...
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Feeding PBKDF2 to SRP verifier creation

There is an older game that solely uses UDP to communicate, and I wanted to add password authentication to the game to facilitate things like experience points and rankings. To this end, I decided to ...
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Creation and deployment of self-signed certificates for a two-machine scenario

Let us assume that I have two computers: client server Now, in the server computer, I set up a legacy ASMX web service which will going to be used by the client. Before the client can connect to to ...
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What are the benefits and risks of various TLS Handshake protocols?

This question asks if it's possible to separate the rest of a TLS session from the handshake for "security reasons". The question wasn't specific on what that "reason" might be. This made me ...
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How to see whether the pcap contains RTP traffic?

I am analyzing the traffic of a VOIP application. I started up wireshark, and made sure no other application was using internet, and then had a a voice call on the application. Wireshark captured some ...
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How can I see whether the e-mails I exchanged with someone have been encrypted?

In my understanding (please correct if applicable), The e-mails sent through a secure server are encrypted in the route between me as client and the mail server, whether this is a local or remote ...
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Best practices for relatively simple API for our clients

I've been reading a lot about many API security considerations, the differences in terminology, OAUTH, OpenID, etc. Although I understand their absolute necessity when it comes to securing an API ...
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Simple File Transfer Protocol

My SIEM has produced something intriguing. I went looking for unauthorized SSH connections, and looked for the SFTP protocol by mistake. I found a Windows web server that is connecting from port 80 to ...
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Secret Santa - implementation that does not require a participant to trust the server

In the Christmas spirit I read Cryptographic Secret Santa from MathOverflow, and then followed the link to another page titled Cryptographic Secret Santa. On this latter page the author explains an ...
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What are the formal methods to analyze Authentication Protocol

I designed an authentication protocol for consumer-producer applications, which barrows features from Kerberos and Tesla. To check the strength of protocol I considered different well known attacks ...
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Can Poodle be fixed in SSLv3 or will it go the way of TLS compression?

Is TLS_FALLBACK_SCSV going to be the fix for servers that wish to keep SSLv3 enabled? If not what actions are being taken, if any, that address the vulnerability besides disabling SSLv3?
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How do session keys in public key cryptography work? [duplicate]

I have read that a session key is symmetric, and it is encrypted by recipient's public key; When "Bob" receives a message, does he decrypt it with his private key and he's then in possession of an ...
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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 ...