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How many bits of information are in a password?

Wandering Thoughts | July 9, 2007, 1:18 a.m. | Original

The number of bits of information in a password are a function of thealphabet that the password is drawn from and how many characters longit is. The formula is:

nbits = ceil(log2(len(alphabet)) * nchars)

So what does that mean? Let's take the case of 8 character longUnix passwords, and do a table:

alphabet	total bits	(bits per character)
lower case ASCII	38	4.7
lower case plus digits	42	5.2
upper and lower

How not to set up your DNS (part 16)

Wandering Thoughts | July 9, 2007, 1:18 a.m. | Original

Sort of presented in the traditional illustrated format:

; sdig ns ibc.com.au.ns1.ibc.com.au.ns2.ibc.com.au.; dig cname ibc.com.au. @ns1.ibc.com.au.[...];; flags: qr aa; QUERY: 1, ANSWER: 1, [...][...];; ANSWER SECTION:ibc.com.au. IN SOA ns1

遊樂場在哪裡

空姐的行李篋 | July 8, 2007, 2:51 p.m. | Original

歸家途上，我看著玻璃窗外中環的景致。

從未在中環正式上班，但這個地方，是我的生活重心，是我回憶中的場景，是我的遊樂場。

小至買零食高跟鞋打掌購物吃飯看戲clubbing約會到學生年代的兼職曾經遇上的男人有發生過的愛情，

不要忘記7

空姐的行李篋 | July 8, 2007, 8 a.m. | Original

如果在男人家中發現不屬你的護膚品，請不動聲色丟棄。

只是小小一支試用裝罷了，女人何必大驚小怪。

不要忘記6

空姐的行李篋 | July 8, 2007, 7:57 a.m. | Original

女人不要自以為是，做盡一切感動男人的事，然後埋怨男人麻木不仁。

男人就是有權不賣帳。

A suggestion for HMAC signature construction

Wandering Thoughts | July 8, 2007, 1:18 a.m. | Original

Here is a useful safety tip if you are constructing HMAC signatures for structured messages,things that you want to parse later: put a format version number intoeither the key or the message.

If you want messages in the old format to fail signature checks so thatthe rest of your code doesn't have to deal with them, put the versionnumber into the key. Put it into the message if you want your code togracefully deal with several generations of message formats; each willstill verify, but the