Boston Linux & UNIX was originally founded in 1994 as part of The Boston Computer Society. We meet on the third Wednesday of each month at the Massachusetts Institute of Technology, in Building E51.

BLU Discuss list archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Discuss] vnc => passphrase entropy

On Fri, Aug 29, 2014 at 1:32 PM, Richard Pieri <richard.pieri at> wrote:
> I have a better solution: use a FIPS 181 password generator to generate
> a "phrase" of nonsense, stuff that into your encrypted keychain, and be
> done with it.

That's fine for JFDI.
Assuming FIPS-181 'words' are mnemonic enough for you.

( Some folks prefer the more mnemonic structure of XKCD "Horse Battery
Staple" to  FIPS "jegewmat". )

But Ned and I are talking natural language entropy theory, so that we
may *compare* strengths with a metric.
[ just as you were talking escrow/centralization theory before, to
compare weaknesses.]

Note that the English-like pronounceability rules of FIPS-181 syllable
structure enforces a weaker structure (thats good here!) than rigid
consonant-vowel alternation, so delivered entropy bits per char are
rather less than log2(26)=4.7b, but it seems far better than English

[ The  FIPS-181 ETAONRISH character frequency of the random urn is
such that 'x' is 10x rarer than 'a' . By itself almost the urn
achieves roughly the same 4.7bits as uniform a..z distribution until a
slight deduction is made for the dipthongs 'ch' etc that it generates
as urn units; but since equal frequency 'a' and 't' are more or less
likely in a position based on vowel/consonants around it, as filtered
in actual use it delivers rather less. Probably still more than 3 bits
though, since a strict CACA|ACAC alternation with this Urn loses less
than a bit per char, not shabby. ]

Bill Ricker
bill.n1vux at

BLU is a member of BostonUserGroups
BLU is a member of BostonUserGroups
We also thank MIT for the use of their facilities.

Valid HTML 4.01! Valid CSS!

Boston Linux & Unix /