### Re: passphrases with more than 160 bits of entropy

On 3/21/06, Travis H. [EMAIL PROTECTED] wrote: Does anyone have a good idea on how to OWF passphrases without reducing them to lower entropy counts? I've frequently seen constructs of this type: H(P), H(0 || P), H(0 || 0 || P), ... If entropy(P) entropy(H), the entries will be independent,

### Re: passphrases with more than 160 bits of entropy

- Original Message - From: Travis H. [EMAIL PROTECTED] Subject: passphrases with more than 160 bits of entropy I was thinking that one could hash the first block, copy the intermediate state, finalize it, then continue the intermediate result with the next block, and finalize that.

### Re: passphrases with more than 160 bits of entropy

Does anyone have a good idea on how to OWF passphrases without reducing them to lower entropy counts? That is, I've seen systems which hash the passphrase then use a PRF to expand the result --- I don't want to do that. I want to have more than 160 bits of entropy involved. What kind of

### Re: passphrases with more than 160 bits of entropy

On Mar 22, 2006, at 4:28 AM, Thierry Moreau wrote: Travis H. wrote: Hi, Does anyone have a good idea on how to OWF passphrases without reducing them to lower entropy counts? That is, I've seen systems which hash the passphrase then use a PRF to expand the result --- I don't want to do that.

### Re: passphrases with more than 160 bits of entropy

On Mar 22, 2006, at 9:04 AM, Perry E. Metzger wrote: Aram Perez [EMAIL PROTECTED] writes: Entropy is a highly discussed unit of measure. And very often confused. Apparently. While you do want maximum entropy, maximum entropy is not sufficient. The sequence of the consecutive numbers 0 -

### Re: passphrases with more than 160 bits of entropy

| Let me rephrase my sequence. Create a sequence of 256 consecutive | bytes, with the first byte having the value of 0, the second byte the | value of 1, ... and the last byte the value of 255. If you measure | the entropy (according to Shannon) of that sequence of 256 bytes, you | have

### Re: passphrases with more than 160 bits of entropy

Aram Perez [EMAIL PROTECTED] writes: On Mar 22, 2006, at 9:04 AM, Perry E. Metzger wrote: Aram Perez [EMAIL PROTECTED] writes: Entropy is a highly discussed unit of measure. And very often confused. Apparently. While you do want maximum entropy, maximum entropy is not sufficient. The

### Re: passphrases with more than 160 bits of entropy

[EMAIL PROTECTED] writes: | Let me rephrase my sequence. Create a sequence of 256 consecutive | bytes, with the first byte having the value of 0, the second byte the | value of 1, ... and the last byte the value of 255. If you measure | the entropy (according to Shannon) of that

### Re: passphrases with more than 160 bits of entropy

Let me rephrase my sequence. Create a sequence of 256 consecutive bytes, with the first byte having the value of 0, the second byte the value of 1, ... and the last byte the value of 255. If you measure the entropy (according to Shannon) of that sequence of 256 bytes, you have maximum

PayPad (www.paypad.com) is an initiative that seems to have JPMorganChase Chase behind it to provide an alternative method for paying transactions on line. You buy a PayPad device, a small card reader with integrated keypad. It connects to your PC using USB. To pay using PayPad at a merchant

### Re: passphrases with more than 160 bits of entropy

Victor Duchovni [EMAIL PROTECTED] writes: Actually calculating the entropy for real-world functions and generators may be intractable... It is, in fact, generally intractable. 1) Kolmogorov-Chaitin entropy is just plain intractable -- finding the smallest possible Turing machine to

### Re: Linux RNG paper

On 3/21/06, [EMAIL PROTECTED] (Heyman, Michael) wrote: Gutterman, Pinkas, and Reinman have produced a nice as-built-specification and analysis of the Linux random number generator. From http://eprint.iacr.org/2006/086.pdf: ... ” Since randomness is often consumed in a multi-user environment,

### Entropy Definition (was Re: passphrases with more than 160 bits of entropy)

On Mar 22, 2006, at 2:05 PM, Perry E. Metzger wrote: Victor Duchovni [EMAIL PROTECTED] writes: Actually calculating the entropy for real-world functions and generators may be intractable... It is, in fact, generally intractable. 1) Kolmogorov-Chaitin entropy is just plain intractable --

### Re: Linux RNG paper

On Wed, Mar 22, 2006 at 02:31:37PM -0800, Bill Frantz wrote: One of my pet peeves: The idea that the user is the proper atom of protection in an OS. My threat model includes different programs run by one (human) user. If a Trojan, running as part of my userID, can learn something about the

### Re: passphrases with more than 160 bits of entropy

Matt Crawford wrote: I so often get irritated when non-physicists discuss entropy. The word is almost always misused. Yes, the term entropy is often misused ... and we have seen some remarkably wacky misusage in this thread already. However, physicists do not have a monopoly on correct