document.write( "Question 710523: I apologize in advance as I am no longer a student and don't mean to waste anyone's time but I am curious if one of the tutors would care to calculate the entropy of \"or better yet\" the number of permutations of a 16 digit password that uses 0 thru 9 and/or 26 letters. I would be curious to know the formula to be able to do the math myself for say 15 digits, 14 digits, 13 digits etc. to understand the entropy. Why? I just dropped some big bucks on an Apricorn 1 TB Padlock USB 3.0 Encrypted Hard Drive with PIN Access. Not doing espionage or anything like that just trying to figure a reasonable passcode. Thank You for your concideration, Jack \n" ); document.write( "
Algebra.Com's Answer #437020 by Alan3354(69443)\"\" \"About 
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calculate the entropy of \"or better yet\" the number of permutations of a 16 digit password that uses 0 thru 9 and/or 26 letters. I would be curious to know the formula to be able to do the math myself for say 15 digits, 14 digits, 13 digits etc. to understand the entropy.
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\n" ); document.write( "If it's not case sensitive, each of the 16 \"digits\" can be one of 36 characters.
\n" ); document.write( "--> 36^16 =~ 7.95866E24 combinations.
\n" ); document.write( "If you try 1000 combinations per second, it'll take 252,367,488,300,000,000,000,000 years to try them all.
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\n" ); document.write( "For 15, 14, 13, etc, it's 36 to the power of the # of characters.
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\n" ); document.write( "If it's case sensitive, each character has 62 possibilities, so it's 62^n, n = # of characters.
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