More in further reading/acknowledgements (+typo)

- Add link to a paper by Seth Lloyd to "Further reading"
- Add a subheading to "Further reading" concerning approaches accounting
  for computation speed.
- Elaborate on the part of Schneier's blog post that proved helpful.
- Revert typo fix in which I erroneously swapped + and -.

content/posts/password-strength.gmi

@@ -74,7 +74,7 @@ A more involved approach to picking a good value might utilize the Plank-Einstei
 
 => https://en.wikipedia.org/wiki/Planck%E2%80%93Einstein_relation Plank-Einstein relation (Wikipedia)
 
-It's also probably a better idea to make this value an estimate for flipping a single bit, and to estimate the average number of bit-flips it takes to make a single password guess. If that bothers you, pick a number b you believe to be a good estimate for a bit-flip-count and calculate P(n-b, e) instead of P(n, e).
+It's also probably a better idea to make this value an estimate for flipping a single bit, and to estimate the average number of bit-flips it takes to make a single password guess. If that bothers you, pick a number b you believe to be a good estimate for a bit-flip-count and calculate P(n+b, e) instead of P(n, e).
 
 What's the temperature of the system? Three pieces of information help us find out:
 
@@ -246,7 +246,7 @@ At that point, a formidable threat would rather use other means to unlock your s
 
 => https://xkcd.com/538/ xkcd 538: Security
 
-## Further reading: an alternate approach
+## Further reading: alternative approaches
 
 See Scott Aaronson's article on Cosmology and Complexity:
 
@@ -258,17 +258,25 @@ He uses an alternative approach to finding the maximum bits we can work with: he
 
 This model takes into account more than just the mass of the observable universe. While we previously found that the MOAC can brute-force a password with 306.76 entropy bits, this model allows the same for up to 405.3 bits.
 
-Another well-known approach to calculating physical limits of computation is Bremermann's limit, which calculates the speed of computation given a finite amount of mass. This article's approach disregards time, focusing only on mass-energy equivalence.
+### Approaches that account for computation speed
+
+This article's approach deliberately disregards computation speed, focusing only on energy required to finish a set of computations. Other approaches account for physical limits on computation speed.
+
+One well-known approach to calculating physical limits of computation is Bremermann's limit, which calculates the speed of computation given a finite amount of mass.
 
 => https://en.wikipedia.org/wiki/Bremermann%27s_limit Bremermann's limit (Wikipedia)
 
+A publication⁵ by Seth Lloyd from MIT further explores limits to computation speed on an ideal 1-kilogram computer:
+
+=> https://arxiv.org/abs/quant-ph/9908043
+
 ## Acknowledgements
 
 Thanks to Barna Zsombor and Ryan Coyler for helping me over IRC with my shaky physics and pointing out the caveats of my approach.
 
 My notes from Thermal Physics weren't enough to write this; various Wikipedia articles were also quite helpful, most of which were linked in the body of the article.
 
-A blog post by Bruce Schneier contained a useful excerpt from his book *Applied Cryptography*⁵ involving setting the minimum energy per computation to kT:
+While I was struggling to come up with a good expression for the minimum energy used per password guess, I stumbled upon a blog post by Bruce Schneier. It contained a useful excerpt from his book *Applied Cryptography*⁶ involving setting the minimum energy per computation to kT:
 
 => https://www.schneier.com/blog/archives/2009/09/the_doghouse_cr.html
 
@@ -284,4 +292,6 @@ I chose a more conservative estimate for T than Schneier did, and a *much* great
 
 ⁴ This is a massive oversimplification; there isn't a single answer to the question "What is the volume of the universe?" Using this speed-of-light approach is one of multiple valid perspectives. The absolute size of the observable universe is much greater due to the way expansion works, but stuffing that into the MOAC's furnace would require moving mass faster than the speed of light.
 
-⁵ Schneier, Bruce. Applied Cryptography, Second Edition, John Wiley & Sons, 1996.
+⁵ Lloyd, S., “Ultimate Physical Limits to Computation,” Nature 406, 1047-1054, 2000.
+
+⁶ Schneier, Bruce. Applied Cryptography, Second Edition, John Wiley & Sons, 1996.

content/posts/password-strength.md

@@ -131,7 +131,7 @@ relation](https://en.wikipedia.org/wiki/Planck%E2%80%93Einstein_relation).
 It's also probably a better idea to make this value an estimate for flipping a single
 bit, and to estimate the average number of bit-flips it takes to make a single
 password guess. If that bothers you, pick a number `b` you believe to be a good
-estimate for a bit-flip-count and calculate `P(n-b, e)` instead of `P(n, e)`.
+estimate for a bit-flip-count and calculate `P(n+b, e)` instead of `P(n, e)`.
 
 What's the temperature of the system? Three pieces of information help us find out:
 
@@ -308,8 +308,8 @@ conservation of energy:
 At that point, a formidable threat would rather use [other
 means](https://xkcd.com/538/) to unlock your secrets.
 
-Further reading: an alternative approach
+Further reading: alternative approaches
-----------------------------------------
+---------------------------------------
 
 Check out Scott Aaronson's article, [Cosmology and
 Complexity](https://www.scottaaronson.com/democritus/lec20.html). He uses an
@@ -320,11 +320,20 @@ This model takes into account more than just the mass of the observable universe
 While we previously found that the MOAC can brute-force a password with 306.76
 entropy bits, this model allows the same for up to 405.3 bits.
 
-Another well-known approach to calculating physical limits of computation is
+### Approaches that account for computation speed
+
+This article's approach deliberately disregards computation speed, focusing only on
+energy required to finish a set of computations. Other approaches account for
+physical limits on computation speed.
+
+One well-known approach to calculating physical limits of computation is
 [Bremermann's limit](https://en.wikipedia.org/wiki/Bremermann%27s_limit), which
 calculates the speed of computation given a finite amount of mass. This article's
 approach disregards time, focusing only on mass-energy equivalence.
 
+[A publication](https://arxiv.org/abs/quant-ph/9908043)[^5] by Seth Lloyd from MIT
+further explores limits to computation speed on an ideal 1-kilogram computer.
+
 Acknowledgements
 ----------------
 
@@ -336,11 +345,13 @@ My notes from Thermal Physics weren't enough to write this; various Wikipedia
 articles were also quite helpful, most of which were linked in the body of the
 article.
 
-A [blog post](https://www.schneier.com/blog/archives/2009/09/the_doghouse_cr.html) by
+While I was struggling to come up with a good expression for the minimum energy used
-Bruce Schneier also contained a useful excerpt from his book *Applied
+per password guess, I stumbled upon a [blog
-Cryptography*[^5] involving setting the minimum energy per computation to `kT`. I
+post](https://www.schneier.com/blog/archives/2009/09/the_doghouse_cr.html) by Bruce
-chose a more conservative estimate for `T` than Schneier did, and a *much* greater
+Schneier. It contained a useful excerpt from his book *Applied Cryptography*[^6]
-source of energy.
+involving setting the minimum energy per computation to `kT`. I chose a more
+conservative estimate for `T` than Schneier did, and a *much* greater source of
+energy.
 
 [^1]: James Massey (1994). "Guessing and entropy" (PDF). Proceedings of 1994 IEEE
   International Symposium on Information Theory. IEEE. p. 204.
@@ -359,4 +370,7 @@ source of energy.
   universe is much greater due to the way expansion works, but stuffing that into the
   MOAC's furnace would require moving mass faster than the speed of light.
 
-[^5]: Schneier, Bruce. Applied Cryptography, Second Edition, John Wiley & Sons, 1996.
+[^5]: Lloyd, S., "Ultimate Physical Limits to Computation," Nature 406.6799,
+  1047-1054, 2000.
+
+[^6]: Schneier, Bruce. Applied Cryptography, Second Edition, John Wiley & Sons, 1996.