Random Uniq Number (only 8-chars)

javascript-clever-random.js

getRandom = function(){	
	var date = new Date().getTime();
	var random = Math.floor((Math.random()*800)+100);
	return(date+random).toString(36);
};

Random Uniq Number (only 8-chars)

by Samuel Ondrek

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• I use this method in my project Markdown mDown Project
• Returns strings simular to hms2udc2, hms2ucwc, hms2ubtt, ..

Why you should use this method?

• Because result is (and always will be) short string
• Because result is always uniq
• Because result is short
• Because to guess next iteration is difficult (without knowledge of method)

How it works?

// miliseconds from 01.01.1970
// you can use different method of time-uniq number
1381778973111

// random (100~999) gets always same lenght of string
// so last string has always same lenght
889

// addition of both numbers for more uniq combination
// also more difficult randomly find correct one
1381778973111889

// convert this to base 36 (no base10, no base16, base36)
// so it's shorter and readable
hms3r897

How to improve code to more secure?

• Change random number lenght Math.floor((Math.random()*8000000)+100)
• Add random string random+'secretHash'.toString(36)
• You can also change string to different base instead of 36

When I cannot use this?

• If your users request code more like 10000x in one second
• .. and if you still want, you should check ifExists

Copyright

• Samuel Ondrek
• Use it where you need, if it's public project, you can add link :)