This might be a duplicate question but as you can see they didn't get the correct answer.
How to uniquely identify a computer?
Uniquely identify one computer
how would you remembers a computers regardless of ip, "browser" cookies, and browser itself. So It will recognize it once you use it from another browser, or ip address. Any ideas?
UPDATE
I found out that there is a possibility using flash cookies:
it seems that it's shared across browsers and clearing the browser cookies does not remove it.
my question now is how can I see my flash cookies and know if that is what facebook is doing?
Ubiquitous availability (95 percent of visitors will probably have flash)
You can store more data per cookie (up to 100 KB)
Shared across browsers, so more likely to uniquely identify a machine
Clearing the browser cookies does not remove the flash cookies. --Joeri Sebrechts
I suppose a flash cookie is a bit more cross browser and persists.
Facebook only remembers based on the cookie in your browser.
The proof to the pudding is if you login and then switch to a different browser, you are not logged in there.
Related
Which technology is used to maintain the user browser or machine identification ? After removing all the browser history and cookies ?
Real Time Scenerio:
I am login to axis internet login through my machine with firefox browser,during the first login it will ask the security question.,after that I removed all my history and cookies of my firefox browser.But again login to my axis internet banking from the same machine,It couldn't ask any security question.
While accessing from different machine at the first time,it will ask the security question and all.,but two different systems are being accessing same internet.
Which technology is available to maintain the user credentials after removing all the client browser histroy and cookies.,
Thanks in advance
As I know some websites use 2 ways to check if the user already visited the website and if so perform the desidered actions.
They use:
Cookies
They store cookies in your browser and then retrive them when needed
IP recognition
They store your IP so even if you delete your cookies they have in their database the information they've stored as cookies and then they can re-add these cookies.
How to avoid this?
You can avoid to be recognized by the website turning off your modem for 10/15 minutes if you have a dynamic IP address. If you have a static one or your dynamic address do not change so often (depend on your ISP) you could use a proxy.
you can use a local storage for this purpose try with this link
I have started to learn PHP a couple of weeks ago, and now I would like to create (even a simpler version would be acceptable for me) a website such as:
www.cookiebot.com/en/start
cookie-checker.com
So I would like to create a form where the user can type the domain from which she/he would like to know which cookies are sent/used in that website.
Whether are third party cookies or not, and so on.
On the Internet I have found several different answers to this question, some people told me is not possible to get such cookies, others told me is possible but they have not been able to explain me, and so on.
So my question is: can somebody explain me theoretically how a website like that one works?
Does PHP have a function to get cookies or cookies information from the website and let the developer read the cookies at least to know what kind of cookie it is?
Or maybe is there any way to read the cookies stored on my computer when I visit a website?
Thank you very much!
No.
The browser explicitly saves cookies on a per-domain and even per-directory basis. When the server sets a cookie, it can specify within limitations whether a cookie is valid for subdomains or not and what path it should be valid for. However, cookies cannot be set cross-domain or read cross-domain. The browser will not send cookies back to other servers, and client-side Javascript has no access to cookies from other domains either.
In short, you cannot have a website which has access to cookies set by some other website. And that is a good thing. Otherwise security would be non existent on the web.
I want to clear all the cookies of a particular website in the users browser when a person runs a php script in my website.
Go through all of your cookies and run this:
setcookie("cookie_name", $site_name, time()-timeout);
You cannot do this as the browser maintains the cookies for that web site, not your web site. This would be a breach in the contract between the web server and the browser.
Also it is up to the browser to handle cookies in the way that it sees fit - after all a cookie is asking the browser to do the web server a favour by storing some info between web page visits from that server (domain).
But if the cookies are from your domain/server then you can ask the browser to either make them time out or give them an invalid value.
Can we Fetch Values from Cross Browser Cookie ???
For Example USer Can use mozilla or chrome or any other browser
when we print_r($_COOKIE);
All Browsers Cookie Will Print.
No, cookies are stored only within one browser's cache. If you want to save data specific to a certain computer you will need to use Flash objects or server side databases
You will never be able to see all cookies set in a browser. Only the ones that are destined for the domain the request was sent to. For more information on cookies and the domain policy see here.
All browsers which have cookies enabled will send data to PHP which is added to $_COOKIE, assuming cookie data has been set...
That said, a browser will only "serve up" cookie data from itself and from the current domain. It cannot read another browser's cookies and it will not let you get data from another website.
It isn't clear what you are asking, so here are three answers:
How can I use cookies and have them work no matter what browser my visitors use?
Cookies are a standard. You use the same HTTP headers (or JavaScript) to set them for all browsers, and all browsers send them to the server in the same way.
How can I access the cookies I set before the user switched browser?
You can't read a cookie stored by (for example) Internet Explorer when the user visits using (also for example) Chrome. Chrome does not have access to the cookies stored by Internet Explorer so cannot send them to the server.
How can I access cookies set by a different website?
You cannot read a cookie stored for a different domain as browsers will only send cookies belonging to a given website to that website (to do otherwise would require vast amounts of bandwidth and be a terrible security problem).
The only cookies your website can read are those that were issued from the same domain to the users current browser.
For security reasons, browsers will only send cookie information to the same domain which issued it. Sometimes, it's even limited to a particular subdomain, rather than being valid for the entire site. This is a very good thing, since cookie information often contains session data which can (partially or wholly) give access to a website account to the holder of a cookie. This is called session hijacking. Basically, if a browser served up all your cookies to every site which requested them, a malicious site owner could take over your accounts on other sites just by making a request to them using the cookie data for that site.
Also, cookies are local to the particular browser that a user is using at the time the cookie is created. This is why if you were to log into your Facebook account from Firefox, you would have to log in again if you switched to Chrome.
In short, what you are asking for is impossible, and it is impossible for very good reasons.
Let a user using Mozilla browser , On three tabs he login to his yahoo account ,gmail and hotmail.
Now if we Clear Recent History , all three session will be cleared.
But at the same time if there is another session in any another browser it will not be cleared.
So What i am trying to ask here is , the cookies and session related details ,browser cache will be in the local computer and it will be cleared on clearing history.
But is it browser specific?
The cookie and all will have any browser specific id , how it will differentiate that now clear the IE history or clear chrome history.
You can in fact use two different accounts on two different browsers at the same time. The browser history/cookies etc are specific to the browser in question.
There isn't a "standard" where browser save their settings, each do it as they file. MSIE might use the Windows Registry while Firefox might use a local database file.
For the server to keep track of a client session a session id is sent to the client. Which the client uses in each request to the server.
On the local computer each browser has it's own way of saving the cookie files. So when you clear the cookies in Firefox, then the cookies saved by Firefox will be deleted. Same thing with Chrome, IE, Safari etc.
They could even be using a own way of serializing the cookies for all that I know.