Instead of checking each and every possible value we check the boundary values only. For eg if the login id has to accept only 6 to 11 alphabets only. Then we check this instance by applying the values like 6-1 5 alphabets --- it should fail 6------------pass 7----------- pass 11------------pass 11+1 12-------fail ie. min-1 max+1 should fail middle of the values should pass. this is boundary value analysis(BVA)
Password Min and Max length should be specify in the requirements.
If more than 6 characters the password should good. If the characters is the combination of alpha characters with special symbols then the password is strong.
I think there is no particular number fixed for Max And Min length password It depends upon the User perspective using the product We can fix that number To test this type of fields there is a tool called TestersDesk Normally We can test the Boundary Value For one instance at one time But the Specialization of this tool is We can test the Several instances at single time
This should be in the [Design] Specs - but it may be the case that the Password may also be case-sensitive and/or need a number(s) too - for example "Password" would be allowed but "password" wouldn't - or the the password may need to be "Password10" etc. I'd also recommend not having a password of "Password" case sensitive or not! Indeed these types of words may be barred. Apologies as I realise my answer comes out of the boundaries (no pun intended) of Boundary Value but I thought it may be of some use / get some fellow testing brains thinking :)