1995-02-02 - How much entropy in a key press?
Header Data
From: Nobody@eniac.ac.siue.edu (Anonymous)
To: cypherpunks@toad.com
Message Hash: 1a41e61d2ddbe6c8f455e83bfe01b05976c673c1d4b429fd720da4e2d037ef6d
Message ID: <199502021456.IAA01951@eniac.ac.siue.edu>
Reply To: N/A
UTC Datetime: 1995-02-02 15:04:00 UTC
Raw Date: Thu, 2 Feb 95 07:04:00 PST
Raw message
From: Nobody@eniac.ac.siue.edu (Anonymous)
Date: Thu, 2 Feb 95 07:04:00 PST
To: cypherpunks@toad.com
Subject: How much entropy in a key press?
Message-ID: <199502021456.IAA01951@eniac.ac.siue.edu>
MIME-Version: 1.0
Content-Type: text/plain
Can anyone tell me how many bits of entropy there are per 7-bit ASCII
character. More specifically, a program wishes to generate a session
key by prompting the user to type N random key presses. The characters
entered are hashed down to 128 bits by MD5 for subsequent use as a key.
What should the value of N be, such that the entropy of the user's
string does not unnecessarily exceed the entropy of the hash?
Thread
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- 1995-02-02 (Thu, 2 Feb 95 07:04:00 PST) - How much entropy in a key press? - Nobody@eniac.ac.siue.edu (Anonymous)
- 1995-02-02 (Thu, 2 Feb 95 08:37:22 PST) - Re: How much entropy in a key press? - Adam Shostack <adam@bwh.harvard.edu>
- 1995-02-03 (Thu, 2 Feb 95 18:26:52 PST) - Re: How much entropy in a key press? - Robert Rothenburg Walking-Owl <rrothenb@ic.sunysb.edu>