1994-07-02 - Re: Password Difficulties

Header Data

From: schneier@chinet.chinet.com (Bruce Schneier)
To: cypherpunks@toad.com
Message Hash: 2d2b636c5f7a2bec95a0171cca6be4286ffa322c39b3c9d6429a2b2d5da1eaeb
Message ID: <m0qKCoT-0002IRC@chinet>
Reply To: <9407021700.AA16651@mycroft.rand.org>
UTC Datetime: 1994-07-02 21:44:18 UTC
Raw Date: Sat, 2 Jul 94 14:44:18 PDT

Raw message

From: schneier@chinet.chinet.com (Bruce Schneier)
Date: Sat, 2 Jul 94 14:44:18 PDT
To: cypherpunks@toad.com
Subject: Re: Password Difficulties
In-Reply-To: <9407021700.AA16651@mycroft.rand.org>
Message-ID: <m0qKCoT-0002IRC@chinet>
MIME-Version: 1.0
Content-Type: text/plain


Figure that each English character has 1.8 bits of entropy.  (This is
a conservative number, because it doesn't take into account case, spacing,
or punctuation.)  If I want a passphrase that will map into a 64-bit 
keyspace, I need at least a 35-chararcter phrase.

I generally assume that I need about one word per byte of key.  Thus, if
I want to generate a 64-bit key, I need an eight-word phrase.

Bruce

Thread

• Return to July 1994

• Return to “Jim Gillogly <jim@acm.org>”
• Return to “kentborg@world.std.com (Kent Borg)”
• Return to ““Perry E. Metzger” <perry@imsi.com>”
• Return to “schneier@chinet.chinet.com (Bruce Schneier)”

• Return to “Stu@nemesis.wimsey.com (Stuart Smith)”

• 1994-07-02 (Sat, 2 Jul 94 01:41:42 PDT) - Re: Password Difficulties - kentborg@world.std.com (Kent Borg)
  • 1994-07-02 (Sat, 2 Jul 94 10:01:13 PDT) - Re: Password Difficulties - Jim Gillogly <jim@acm.org>
    • 1994-07-02 (Sat, 2 Jul 94 14:44:18 PDT) - Re: Password Difficulties - schneier@chinet.chinet.com (Bruce Schneier)
  • 1994-07-04 (Mon, 4 Jul 94 04:37:35 PDT) - Re: Password Difficulties - Stu@nemesis.wimsey.com (Stuart Smith)
  • 1994-07-05 (Tue, 5 Jul 94 10:27:03 PDT) - Re: Password Difficulties - “Perry E. Metzger” <perry@imsi.com>