I started using PHP a couple of months ago. For the sake of creating a login system for my website, I read about cookies and sessions and their differences (cookies are stored in the user's browser and sessions on the server). At that time, I preferred cookies (and who does not like cookies?!) and just said: "who cares? I don't have any good deal with storing it in my server", so, I went ahead and used cookies for my bachelor graduation project. However, after doin' the big part of my app, I heard that for the particular case of storing user's ID, sessions are more appropriate. So I started thinking about what would I say if the jury asks me why have you used cookies instead of sessions? I have just that reason (that I do not need to store internally information about the user). Is that enough as a reason? or it's more than that?
Could you please tell me about advantages/disadvantages of using cookies for keeping User's ID?
感谢大家在StackOverflow!
当您将#ID保存为cookie以识别登录用户时，您实际上是在向与他们无关的用户显示数据。此外，如果第三方试图在他们的浏览器中设置随机id作为cookie数据，他们将能够使服务器相信他们是用户，而实际上他们不是。这就是缺乏安全感。
您已经使用了cookie，正如您所说，您已经完成了项目的大部分。此外，cookie具有保留较长时间的特权，而会话结束得更快。所以会话在这种情况下不适合。在现实中，许多著名和流行的网站和服务使用cookie，你可以保持登录很长一段时间。但是如何使用他们的方法来创建更安全的登录过程呢?
here's the idea: you can help the way you use cookies: If you use random keys instead of IDs to recognize logged-in users, first, you don't leak your primary data to random users, and second, If you consider the Random key large enough, It will be harder for anyone to guess a key or create a random one. for example you can save a 40 length key like this in User's browser:
"KUYTYRFU7987gJHFJ543JHBJHCF5645UYTUYJH54657jguthfn"
and it will be less likely for anyone to create the exact key and pretend to be someone else.
SESSIONS ENDS WHEN USER CLOSES THEIR BROWSER,
COOKIES END DEPENDING ON THE LIFETIME YOU SET FOR IT. SO THEY CAN LAST FOR YEARS
这是你选择的主要区别，
如果你想让id长时间被记住，那么你需要使用cookie;否则，如果你只是想让网站识别用户的访问，那么只有会话是可行的。
会话存储在php服务器将生成的文件中。为了记住哪个文件是针对哪个用户的，php还将在用户的浏览器上设置一个cookie，保存这个会话文件id，这样在用户下次访问时，php将读取这个文件并重新加载会话。
现在php默认每隔一段时间清除会话，并且会话的命名约定使其自动过期。此外，一旦浏览器关闭或历史记录被清除，浏览器将不会保留保存会话id的cookie。
值得注意的是，现在的浏览器还支持另一种存储引擎，如LocalStorage, SessionStorage和其他webdb引擎，javascript代码可以使用这些引擎将数据保存到您的计算机中以记住您。例如，如果你打开Facebook内部的javascript控制台，并输入“localStorage”，你会看到Facebook使用的所有变量来记住你没有cookie。
