6
votes
1answer
3k views

Is this how to implement CTR around a system that only implements CBC, CFB, CTS, ECB and OFB?

The encryption library in my programming language does not support CTR, though it supports CBC, CFB, CTS, ECB and OFB. I'm assuming it is theoretically possible to securely implement CTR around one ...
13
votes
2answers
3k views

Secure communication between applications using SSL Certificates

I am looking for a way how to secure communication between our applications. There is a "server" application listening on some TCP port and "client" application which is communicating with the ...
0
votes
1answer
354 views

Is using a local DNS cache server more secure than using a DNS server from a router?

Is using a local DNS cache server imore secure than using a DNS server from a router?
8
votes
4answers
24k views

Tips for a secure iptables config to defend from attacks. (client side!)

Own examples: ############### # KERNEL PARAMETER CONFIGURATION # PREVENT YOU SYSTEM FROM ANSWERING ICMP ECHO REQUESTS echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_all # DROP ICMP ECHO-REQUEST ...
9
votes
1answer
385 views

Optimal variable sizes in the Secure Remote Password protocol

I am implementing the Secure Remote Password protocol: U = <username> --> <-- s = <salt from passwd file> a = random() A = g^a ...
12
votes
3answers
2k views

When using AES and CBC, can the IV be a hash of the plaintext?

[Originally on programmers.stackexchange.com with title: Can you encrypt with AES+CBC and search the encrypted data] Basically, I'm going to go with Advanced Encryption Standard with either ...
5
votes
2answers
4k views

Tool or Process to check for AES-NI support on processor?

In another question, Thomas' answer mentioned the AES-NI instruction set, which piqued my curiosity. Is there a tool or process available out there to check whether the instruction set is available ...
5
votes
2answers
646 views

Digital Forensics and Pentesting: what now?

So, i want to enter the security field, and i'm leaning towards security auditing, digital forensics, and reverse engineering. i'm in school right now, i'm studying x86 ASM, exploring Linux, and soon ...
8
votes
1answer
1k views

How to choose a stream cipher

Are there high-speed ciphers designed for things like internet streams without sacrificing security? There are so many options that operate in stream mode. How would one choose a cipher?
6
votes
2answers
674 views

Implementing Secure Remote Password: Constructing the verifier

The SRP protocol as described in RFC 2945 generates the password verifier: x = SHA(<salt> | SHA(<username> | ":" | <raw password>))` v = g^x % N I have three questions: why use ...
13
votes
2answers
3k views

Encryption strategies for multi users access in production systems

I am pretty unknown to encryption strategies in production environments. So my concern is to find a solution how to strongly encrypt data, but make it available to multiple users with different keys. ...
17
votes
2answers
4k views

Why is it always `HASH( salt + password )` that we recommend?

Browsing over this site, many forums, online articles, there's always one specific way we're suggesting to store a password hash: function (salt, pass) { return ( StrongHash(salt + pass) ) } But ...
3
votes
1answer
96 views

Differing scrambling parameter generation methods in Secure Remote Protocol

RFC 2945 (The SRP Authentication and Key Exchange System) states, The parameter u is a 32-bit unsigned integer which takes its value from the first 32 bits of the SHA1 hash of B, MSB first. ...
6
votes
3answers
1k views

Using Secure Remote Password without sending the username in the clear

To initiate a key exchange using the SRP protocol the client sends the username so the server can look up the salt and password verifier. Is there a simple way to change this so that an evesdropper ...
5
votes
1answer
280 views

Using Secure Remote Password without embedding the modulus

The SRP protocol as described by the author assumes that the large safe prime modulus and generator are embedded into the client and server rather than being transmitted as part of the protocol. ...
6
votes
1answer
4k views

Obtain credentials by spoofing WPA/WPA2 Enterprise network?

I have a large scale wireless network secured using WPA/WPA2 Enterprise authentication. Recently, I was made aware of the possibility that someone may use a dd-wrt router and a computer to spoof the ...
0
votes
2answers
543 views

How does WikiLeaks(Julian Assange) get the US Embassy cables? [closed]

How does this guy get these cables? Are those cables routed through a single node, where this guy got it? If so, How it is possible? I mean, how that single point came under the control of Julian ...
14
votes
2answers
4k views

Hiding user account names from unauthenticated RDP sessions

This is for a Windows 7 Ultimate system, which is not a member of a domain. When I log into the system locally, I am required to either manually enter my user ID or authenticate with biometrics. The ...
8
votes
1answer
782 views

Is a 2047-bit prime weaker than a 2048-bit prime?

I have a safe prime generator I'd like to speed up. I can benefit from a significant performance gain if the high order bit in the returned prime can be either 1 or 0. The returned prime would be ...
9
votes
2answers
810 views

Cross site scripting verification on a field which does not accept more than 20 characters

While performing penetration testing, I got stuck to a point. There is a text field which does not accept more than 20 characters(server side validation). I inserted following piece of code to check ...
11
votes
2answers
377 views

What problems does this “recover account” procedure have?

On a website I run I have implemented this procedure for account recovery (forgotten password procedure). I would like to know whether there are any issues with it that I have not spotted, that make ...
13
votes
3answers
34k views

How do you discover what permissions an AD group has, if you have no documentation?

You just got hired at company A and the old administrator is no longer there. Requests start coming through for adding users to the internet restrict group. When you look at the groups none of the ...
13
votes
2answers
889 views

How many iterations of Rabin-Miller should be used to generate cryptographic safe primes?

I am generating a 2048-bit safe prime for a Diffie-Hellman-type key, p such that p and (p-1)/2 are both prime. How few iterations of Rabin-Miller can I use on both p and (p-1)/2 and still be ...
15
votes
2answers
932 views

How does varying character type increase strength of password?

When creating a new password, people often recommend you use both uppercase and lowercase characters, numbers, and symbols. How does adding any of these increase the strength of a password? There ...
20
votes
2answers
886 views

A phone call hack

The other day, I got a call from a relative with an email problem. After a bit more discussion, it turns out that two days previously, a man phoned my relative: stated he was from microsoft; asked ...
16
votes
2answers
991 views

In what scenarios is relying on source IP address as a security control acceptable/unacceptable?

I've noticed that there's a number of questions where relying on source IP address as a control gets mentioned and in most gets dismissed as being unreliable. I'd be interested in hearing from anyone ...
6
votes
2answers
6k views

Testing SQL injection using sqlmap

I'm just started using sqlmap to test for possible SQL injection attacks. I have got a website which is vulnerable: C:\Python27>python xxx\sqlmap\sqlmap.py -u http://www.example.com/page.php?id=1 ...
7
votes
2answers
301 views

Profiling attackers via adaptive games: “Strange game, the only winning move is not to play”

Use of Game Design to Profile Attackers: Interested in any research that links concepts in game design to security systems in an effort to profile the attacker's identity, motives, skills, etc.; if ...
33
votes
2answers
46k views

How to estimate the time needed to crack RSA encryption?

How to estimate the time needed to crack RSA encryption? I mean the time needed to crack Rsa encryption with key length of 1024, 2048, 3072, 4096, 5120, 6144, 5120, 7168, 8192, 9216, 10240, 11264, ...
0
votes
1answer
116 views

WLAN Router authentification [duplicate]

Possible Duplicate: How can I ensure that I connect to the right wireless Access Point? Is it true, that WLAN routers aren't authenticated by clients? The only "authentication" is SSID and ...
11
votes
3answers
2k views

How to exchange RSA public keys safely between two parties?

How to exchange RSA public keys safely between two parties via internet?
5
votes
1answer
101 views

Modeling vectors of an unknown exploit

Looking for a formula and parameters to feed it that will aid in the isolation of relationships within a system when the origin and cause of an exploit within it is unknown. Here's an example of an ...
8
votes
3answers
347 views

Verify a website user is behind corporate firewall?

We have a public ecommerce website hosted at our datacenter onsite. For people who are within the corporate firewall hitting the website I want to display profiling information about the request of ...
7
votes
1answer
832 views

How to get hold of and use WPA session keys?

I'm testing sniffing and decrypting my WPA2 wifi network traffic. But when using airdecap to decrypt the capture file (created by airodump) using my WPA passphrase I only get broadcast traffic. If I ...
5
votes
3answers
6k views

Resolving an IP address of a Remote machine to its MAC address

I wanted to know whether its possible to get the MAC address of remote node (computer/Access Point) if I know its IP address. I have heard that if someone sends you an email (even through gmail), you ...
4
votes
4answers
711 views

Ensuring a web-service only processes requests from specific computers

I'm in the process of designing a system that consists a client application and a single web-service. The client is distributed on several machines (installed by me or a colleague), and the ...
12
votes
5answers
502 views

How can citizens prevent government-led Internet blackouts?

The United Nations now considers Internet access a basic human right. [PDF] Despite the questionable effectiveness of Internet blackouts in silencing a populace and preventing uprisings1, it's ...
15
votes
4answers
2k views

Threat assesment for a captive portal

I am interested in setting up a captive portal on a wireless network. From what I understand I would do this by initially having all guests in a temporary vlan, moving them to the real vlan when ...
17
votes
3answers
2k views

Is it a vulnerability to display exception messages in an error page?

Our web application has an error page that displays the absolute URL path and query of the page on which the error occurred, the date/time of the error, and the exception message. (We do not display ...
10
votes
6answers
2k views

Security of SHA256 and Bitcoins

The Bitcoin network use SHA256 as a core component to it's design. I'm no expert on cryptography, but it seems to me it usually is only a matter of time before security vulnerabilities are discovered ...
20
votes
3answers
2k views

Help me find a lightweight threat modeling framework

We're a small company and we do not have resources that we can dedicate to heavyweight threat modeling. However, if we could find a threat modeling framework that was pretty lightweight I think there ...
29
votes
5answers
4k views

Open Source vs Closed Source Systems

My understanding is that open source systems are commonly believed to be more secure than closed source systems. Reasons for taking either approach, or combination of them, include: cultural norms, ...
23
votes
6answers
21k views

Security risk of PING?

I have been told that PING presents a security risk, and it's a good idea to disable/block it on production web servers. Some research tells me that there are indeed security risks. Is it common ...
13
votes
5answers
1k views

Is there a digital “safety deposit box” equivalent?

Digital safety deposit boxes: do they exist? if yes, are (any|they) trustworthy? There are many bricks and mortar financial institutions where one can rent a locked box in a locked room and be ...
6
votes
3answers
224 views

Spamming exploits without user detection

So I asked this question because I had thought that attackers would have a way to identify client software, because surely if 100 different exploits were spammed against a users machine they would ...
7
votes
2answers
876 views

Any advantage to securing WiFi with a PSK, other than to keep out unauthorized

As I understand WiFi with a PSK, such as WPA(2)-PSK or WEP, anyone on the same network can decrypt anyone elses packets because everybody has the same key. In which case, if you are not going to ...
4
votes
1answer
4k views

Windows task manager can see all processes as non administrator without permission

On Windows Server 2008 R2 operating as a standard user, when I open Task Manager I can see all the processes from different users on the system. I have the option to click "Show all processes" which ...
7
votes
6answers
3k views

Is denying login after incorrect attempts ineffective?

Generally denying login attempts after X amounts of incorrect attempts for Y amount of tries is a very basic way to prevent bruteforce attempts or malicious login attempts. Yet, surely doing this is ...
4
votes
2answers
139 views

Can my /boot be compromised if I Suspend my notebook?

So if I use e.g.: LUKS, and I always suspend my notebook, then are there any methods to modify the unencrypted /boot? It contains the kernel! Or if someone tries (evil maid) to modify the /boot then ...
6
votes
1answer
2k views

Using TPM for full disc encryption?

E.g.: Can I make a better full disc encryption with e.g.: LUKS using the TPM? How?

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