PUP authors win a record number of PROSE awards

On February 2, 2017, the Professional and Scholarly Publishing Division of the Association of American Publishers announced the 41st PROSE Awards winners in Washington, DC. We are delighted that 2017 was a record year for PUP, with 24 Awards for titles across disciplines, and we are honored to have our books recognized alongside those of our esteemed colleagues in book publishing. We warmly congratulate all of the winners.

The Urbanism of Frank Lloyd Wright
Neil Levine
Winner of the 2017 PROSE Award in Architecture & Urban Planning, Association of American Publishers

Bosch and Bruegel: From Enemy Painting to Everyday Life
Joseph Leo Koerner
Winner of the 2017 PROSE Award in Art History & Criticism, Association of American Publishers

The Rise of a Prairie Statesman: The Life and Times of George McGovern
Thomas J. Knock
Winner of the 2017 PROSE Award in Biography & Autobiography, Association of American Publishers

Fashion, Faith, and Fantasy in the New Physics of the Universe
Roger Penrose
Winner of the 2017 PROSE Award in Chemistry & Physics, Association of American Publishers

The Cosmic Web: Mysterious Architecture of the Universe
J. Richard Gott
Winner of the 2017 PROSE Award in Cosmology & Astronomy, Association of American Publishers

The Curse of Cash
Kenneth S. Rogoff
Winner of the 2017 PROSE Award in Economics, Association of American Publishers

“Keep the Damned Women Out”: The Struggle for Coeducation
Nancy Weiss Malkiel
Winner of the 2017 PROSE Award in Education Practice, Association of American Publishers

Democracy for Realists: Why Elections Do Not Produce Responsive Government
Christopher H. Achen and Larry M. Bartels
Winner of the 2017 PROSE Award in Government & Politics, Association of American Publishers

Strange Glow: The Story of Radiation
Timothy J. Jorgensen
Winner of the 2017 PROSE Award in History of Science, Medicine & Technology, Association of American Publishers

The Philosopher: A History in Six Types
Justin E.H. Smith
Winner of the 2017 PROSE Award in Philosophy, Association of American Publishers

The Bees in Your Backyard: A Guide to North America’s Bees
Joseph S. Wilson and Olivia J. Messinger Carril
Winner of the 2017 PROSE Award in Single Volume Reference/Science, Association of American Publishers

The Rise and Fall of American Growth: The U.S. Standard of Living since the Civil War
Robert J. Gordon
Winner of the 2017 PROSE Award in U.S. History, Association of American Publishers

Bitcoin and Cryptocurrency Technologies: A Comprehensive Introduction
Arvind Narayanan (et al.)
Honorable Mention for the 2017 PROSE Award in Computing & Information Sciences, Association of American Publishers

Welcome to the Universe
Neil deGrasse Tyson, J. Richard Gott, and Michael A. Strauss
Honorable Mention for the 2017 PROSE Award in Cosmology & Astronomy, Association of American Publishers

Success and Luck: Good Fortune and the Myth of Meritocracy
Robert H. Frank
Honorable Mention for the 2017 PROSE Award in Economics, Association of American Publishers

Wisdom’s Workshop: The Rise of the Modern University
James Axtell
Honorable Mention for the 2017 PROSE Award in Education Theory, Association of American Publishers

Blue Skies over Beijing: Economic Growth and the Environment in China
Matthew E. Kahn and Siqi Zheng
Honorable Mention for the 2017 PROSE Award in Environmental Science, Association of American Publishers

A Culture of Growth: The Origins of the Modern Economy
Joel Mokyr
Honorable Mention for the 2017 PROSE Award in European & World History, Association of American Publishers

ISIS: A History
Fawaz A. Gerges
Honorable Mention for the 2017 PROSE Award in Government & Politics, Association of American Publishers

Ireland’s Immortals: A History of the Gods of Irish Myth
Mark Williams
Honorable Mention for the 2017 PROSE Award in Literature, Association of American Publishers

Following the Wild Bees: The Craft and Science of Bee Hunting
Thomas D. Seeley
Honorable Mention for the 2017 PROSE Award in Popular Science & Popular Mathematics, Association of American Publishers

Silent Sparks
Sara Lewis
Honorable Mention for the 2017 PROSE Award in Popular Science & Popular Mathematics, Association of American Publishers

The Princeton History of Modern Ireland
Richard Bourke and Ian McBride, eds.
Honorable Mention for the 2017 PROSE Award in Single Volume Reference/Humanities & Social Sciences, Association of American Publishers

Group Theory in a Nutshell for Physicists
A. Zee
Honorable Mention for the 2017 PROSE Award in Textbook/Best in Physical Sciences & Mathematics, Association of American Publishers

**

PROSE

Brian Kernighan on what we all need to know about computers

KernighanLaptops, tablets, cell phones, and smart watches: computers are inescapable. But even more are invisible, like those in appliances, cars, medical equipment, transportation systems, power grids, and weapons. We never see the myriad computers that quietly collect, share, and sometimes leak vast amounts of personal data about us, and often don’t consider the extent to which governments and companies increasingly monitor what we do. In Understanding the Digital World, Brian W. Kernighan explains, in clear terms, not only how computers and programming work, but also how computers influence our daily lives. Recently, Kernighan answered some questions about his new book.

Who is this book for? What kind of people are most likely to be interested?

BK: It’s a cliché, but it really is aimed at the proverbial “educated layman.” Everyone uses computers and phones for managing their lives and communicating with other people. So the book is for them. I do think that people who have some technical background will enjoy it, but will also find that it will help their less technical friends and family understand.

What’s the basic message of the book?

BK: Computers—laptops, desktops, tablets, phones, gadgets—are all around us. The Internet lets our computers communicate with us and with other computers all over the world. And there are billions of computers in infrastructure that we rely on without even realizing its existence. Computers and communications systems have changed our lives dramatically in the past couple of decades, and will continue to do so. So anyone who hopes to be at least somewhat informed ought to understand the basics of how such things work. One major concern has been the enormous increase in surveillance and a corresponding reduction in our personal privacy. We are under continuous monitoring by government agencies like the NSA in the United States and similar ones in other countries. At the same time, commercial interests track everything we do online and with our phones. Some of this is acceptable, but in my opinion, it’s gone way too far. It’s vital that we understand better what is being done and how to reduce the tracking and spying. The more we understand about how these systems work, the more we can defend ourselves, while still taking advantage of the many benefits they provide. For example, it’s quite possible to explore interesting and useful web sites without being continuously tracked. You don’t have to reveal everything about yourself to social networks. But you have to know something about how to set up some defenses. More generally, I’m trying to help the reader to reach a better than superficial understanding of how computers work, what software is and how it’s created, and how the Internet and the Web operate. Going just a little deeper into these is totally within the grasp of anyone. The more you know, the better off you will be; knowing even a little about these topics will put you ahead of the large majority of people, and will protect you from any number of foolish behaviors.

Can you give us an example of how to defend ourselves against tracking by web sites?

BK: Whenever you visit a web site, a record is made of your visit, often by dozens of systems that are collecting information that can be used for targeted advertising. It’s easy to reduce this kind of tracking by turning off third-party cookies and by installing some ad-blocking software. You can still use the primary site, but you don’t give away much if anything to the trackers, so the spread of information about you is more limited.

If I don’t care if companies know what sites I visit, why should I be worried?

BK: “I’ve got nothing to hide,” spoken by an individual, or “If you have nothing to hide, you have nothing to fear,” offered by a government, are pernicious ideas. They frame the discussion in such a way as to concede the point at the beginning. Of course you have nothing to hide. If that’s true, would you mind showing me your tax returns? How did you vote in the last election? What’s your salary? Could I have your social security number? Could you tell me who you’ve called in the past year? Of course not—most of your life is no one else’s business.

What’s the one thing that you would advise everyone to do right now to improve their online privacy and security?

BK: Just one thing? Learn more about how your computer and your phone work, how the Internet works, and how to use all of them wisely. But I would add some specific recommendations, all of which are easy and worthwhile. First, in your browser, install defensive extensions like like AdBlock and Ghostery, and turn off third-party cookies. This will take you less than ten minutes and will cut your exposure by at least a factor of ten. Second, make sure that your computer is backed up all the time; this protects you against hardware failure and your own mistakes (both of which are not uncommon), and also against ransomware (though that is much less a risk if you are alert and have turned on your defenses). Third, use different passwords for different sites; that way, if one account is compromised, others will not be. And don’t use your Facebook or Google account to log in to other sites; that increases your vulnerability and gives away information about you for minor convenience. Finally, be very wary about clicking on links in email that have even the faintest hint of something wrong. Phishing attacks are one of the most common ways that accounts are compromised and identities stolen.

KernighanBrian W. Kernighan is a professor in the Department of Computer Science at Princeton University. He is the coauthor of ten other books, including the computing classic The C Programming Language (Prentice Hall). He is the author of Understanding the Digital World: What You Need to Know about Computers, the Internet, Privacy, and Security.

Bird Fact Friday – Weekly Warbler: Yellow warbler

Good news for all the birders out there! We are hosting a Warbler Guide App giveaway today on Instagram (princetonupress). Follow us and like our post to enter, and we will be randomly selecting a winner among the participants on Monday, Feb 6.

From page 466-467 in The Warbler Guide:

The yellow warbler has a plain face with round, black eyes. Its stout black bill stands out against its yellow face. There is yellow edging on its wing feathers. Some of the yellow warblers show red streaking in breast; however, the amount of red beast streaking is variable, usually dull or lacking in females. The yellow warbler is a very widespread species: it can be found in low trees and woodland edges, and often in willows or wet areas.

The Warbler Guide
Tom Stephenson & Scott Whittle
Drawings by Catherine Hamilton
Warbler Guide App
Species Account Example: American Redstart Male

Warblers are amwarblerong the most challenging birds to identify. They exhibit an array of seasonal plumages and have distinctive yet oft-confused calls and songs. The Warbler Guide enables you to quickly identify any of the 56 species of warblers in the United States and Canada. This groundbreaking guide features more than 1,000 stunning color photos, extensive species accounts with multiple viewing angles, and an entirely new system of vocalization analysis that helps you distinguish songs and calls.

The Warbler Guide revolutionizes birdwatching, making warbler identification easier than ever before. For more information, please see the author videos on the Princeton University Press website.

More than superstition: Happy Groundhog Day!

The groundhog may have no talent for predicting the arrival of spring, but it surely can enlighten us on animals’ reactions to changing weather patterns. According to biologist Daniel T. Blumstein, celebrating Groundhog Day is about more than a superstition. In the Washington Post, he notes, “Understanding how individual groundhogs respond to environmental change is essential if we want to predict how animals will react to global warming and other human-driven habitat shifts.”

And no worries if Punxsutawney Phil sees his shadow on Groundhog Day, after all, if winter comes, can spring be far behind?

To know more about this mysterious mammal, check out Roland W. Kays and Don E. Wilson’s book Mammals of North America, an indispensable guide for amateur naturalists and professional zoologists alike.


Mammals of North America
Second Edition
Roland W. Kays & Don E. Wilson
Introduction
Mammals of North America APP

Covering 20 species recognized since 2002 and including 13 new color plates, this fully revised edition of Mammals of North America illustrates all 462 known mammal species in the United States and Canada—each in beautiful color and accurate detail. With a more up-to-date species list than any other guide, improved facing-page descriptions, easier-to-read distribution maps, updated common and scientific names, and track and scat illustrations, this slim, light, and easy-to-use volume is the must-have source for identifying North American mammals.

 

 

Bird Fact Friday – Weekly Warber: Northern parula

Welcome back to the warblers!

From page 366-367 in The Warbler Guide:

The northern parula is very small and active. It has bright yellow throat and breast, and green back patch surrounded by blue. It has broken eye-arcs, which look prominent on its plain bluish face, black lores, and white wing bars. The northern parula is an acrobatic feeder, often hanging upside down. Its bill is brightly bicolored, unlike most other warblers. It is featured on the book cover of The Warbler Guide!

The Warbler Guide
Tom Stephenson & Scott Whittle
Drawings by Catherine Hamilton
Warbler Guide App
Species Account Example: American Redstart Male

Warblers are amwarblerong the most challenging birds to identify. They exhibit an array of seasonal plumages and have distinctive yet oft-confused calls and songs. The Warbler Guide enables you to quickly identify any of the 56 species of warblers in the United States and Canada. This groundbreaking guide features more than 1,000 stunning color photos, extensive species accounts with multiple viewing angles, and an entirely new system of vocalization analysis that helps you distinguish songs and calls.

The Warbler Guide revolutionizes birdwatching, making warbler identification easier than ever before. For more information, please see the author videos on the Princeton University Press website.

David Alan Grier: The Light of Computation

by David Alan Grier

When one figure steps into the light, others can be seen in the reflected glow. The movie Hidden Figures has brought a little light to the contributions of NASA’s human computers. Women such as Katherine Goble Johnson and her colleagues of the West Area Computers supported the manned space program by doing hours of repetitive, detailed orbital calculations. These women were not the first mathematical workers to toil in the obscurity of organized scientific calculation. The history of organized computing groups can be traced back to the 17th century, when a French astronomer convinced three friends to help him calculate the date that Halley’s comet would return to view. Like Johnson, few human computers have received any recognition for their labors. For many, only their families appreciated the work that they did. For some, not even their closest relatives knew of their role in the scientific community.

GrierMy grandmother confessed her training as a human computer only at the very end of her life. At one dinner, she laid her fork on the table and expressed regret that she had never used calculus. Since none of us believed that she had gone to college, we dismissed the remark and moved the conversation in a different direction. Only after her passing did I find the college records that confirmed she had taken a degree in mathematics from the University of Michigan in 1921. The illumination from those records showed that she was not alone. Half of the twelve mathematics majors in her class were women. Five of those six had been employed as human computers or statistical clerks.

By 1921, organized human computing was fairly common in industrialized countries. The governments of the United States, Germany, France, Great Britain, Japan, and Russia supported groups that did calculations for nautical almanacs, national surveys, agricultural statistics, weapons testing, and weather prediction. The British Association for the Advancement of Science operated a computing group. So did the Harvard Observatory, Iowa State University, and the University of Indiana. One school, University College London, published a periodical for these groups, Tracts for Computers.

While many of these human computers were women, most were not. Computation was considered to be a form of clerical work, which was still a career dominated by men. However, human computers tended to be individuals who faced economic or social barriers to their careers. These barriers prevented them from becoming a scientist or engineer in spite of their talents. In the book When Computers Were Human, I characterized them as “Blacks, women, Irish, Jews and the merely poor.” One of the most prominent computing groups of the 20th century, the Mathematical Tables Project, hired only the impoverished. It operated during the Great Depression and recruited its 450 computers from New York City’s unemployment rolls.

During its 10 years of operations, the Math Tables Project toiled in obscurity. Only a few members of the scientific community recognized its contributions. Hans Bethe asked the group to do the calculations for a paper that he was writing in the physics of the sun. The engineer Philip Morse brought problems from his colleagues at MIT. The pioneering computer scientist John von Neumann asked the group to test a new mathematical optimization technique after he was unable to test it on the new ENIAC computer. However, most scientists maintained a distance between themselves and the Mathematical Tables Project. One member of the Academy of Science explained his reservations about the Project with an argument that came to be known as the Computational Syllogism. Scientists, he argued, are successful people. The poor, he asserted, are not successful. Therefore, he concluded, the poor cannot be scientists and hence should not be employed in computation.

Like the human computers of NASA, the Mathematical Tables Project had a brief moment in the spotlight. In 1964, the leader of the Project, Gertrude Blanch, received a Federal Woman’s Award from President Lyndon Johnson for her contributions to the United States Government. Yet, her light did not shine far enough to bring recognition to the 20 members of the Math Tables Project who published a book, later that year, on the methods of scientific computing. The volume became one of the most highly sold scientific books in history. Nonetheless, few people knew that it was written by former human computers.

The attention to Katherine Goble Johnson is welcome because it reminds us that science is a community endeavor. When we recognize the authors of scientific articles, or applaud the distinguished men and women who receive Nobel Prizes (or in the case of computer science, Turing Medals) we often fail to see the community members that were essential to the scientific work. At least in Hidden Figures, they receive a little of the reflected light.

David Alan Grier is the author of When Computers Were Human. He writes “Global Code” for Computer magazine and products the podcast “How We Manage Stuff.” He can be reached at grier@gwu.edu.

Cipher challenge #3 from Joshua Holden: Binary ciphers

The Mathematics of Secrets by Joshua Holden takes readers on a tour of the mathematics behind cryptography. Most books about cryptography are organized historically, or around how codes and ciphers have been used in government and military intelligence or bank transactions. Holden instead focuses on how mathematical principles underpin the ways that different codes and ciphers operate. Discussing the majority of ancient and modern ciphers currently known, The Mathematics of Secrets sheds light on both code making and code breaking. Over the next few weeks, we’ll be running a series of cipher challenges from Joshua Holden. The last post was on subliminal channels. Today’s is on binary ciphers:

Binary numerals, as most people know, represent numbers using only the digits 0 and 1.  They are very common in modern ciphers due to their use in computers, and they frequently represent letters of the alphabet.  A numeral like 10010 could represent the (1 · 24 + 0 · 23 + 0 · 22 + 1 · 2 + 0)th = 18th letter of the alphabet, or r.  So the entire alphabet would be:

 plaintext:   a     b     c     d     e     f     g     h     i     j
ciphertext: 00001 00010 00011 00100 00101 00110 00111 01000 01001 01010

 plaintext:   k     l     m     n     o     p     q     r     s     t
ciphertext: 01011 01100 01101 01110 01111 10000 10001 10010 10011 10100

 plaintext:   u     v     w     x     y     z
ciphertext: 10101 10110 10111 11000 11001 11010

The first use of a binary numeral system in cryptography, however, was well before the advent of digital computers. Sir Francis Bacon alluded to this cipher in 1605 in his work Of the Proficience and Advancement of Learning, Divine and Humane and published it in 1623 in the enlarged Latin version De Augmentis Scientarum. In this system not only the meaning but the very existence of the message is hidden in an innocuous “covertext.” We will give a modern English example.

Suppose we want to encrypt the word “not” into the covertext “I wrote Shakespeare.” First convert the plaintext into binary numerals:

   plaintext:   n      o     t
  ciphertext: 01110  01111 10100

Then stick the digits together into a string:

    011100111110100

Now we need what Bacon called a “biformed alphabet,” that is, one where each letter can have a “0-form” and a “1-form.”We will use roman letters for our 0-form and italic for our 1-form. Then for each letter of the covertext, if the corresponding digit in the ciphertext is 0, use the 0-form, and if the digit is 1 use the 1-form:

    0 11100 111110100xx
    I wrote Shakespeare.

Any leftover letters can be ignored, and we leave in spaces and punctuation to make the covertext look more realistic. Of course, it still looks odd with two different typefaces—Bacon’s examples were more subtle, although it’s a tricky business to get two alphabets that are similar enough to fool the casual observer but distinct enough to allow for accurate decryption.

Ciphers with binary numerals were reinvented many years later for use with the telegraph and then the printing telegraph, or teletypewriter. The first of these were technically not cryptographic since they were intended for convenience rather than secrecy. We could call them nonsecret ciphers, although for historical reasons they are usually called codes or sometimes encodings. The most well-known nonsecret encoding is probably the Morse code used for telegraphs and early radio, although Morse code does not use binary numerals. In 1833, Gauss, whom we met in Chapter 1, and the physicist Wilhelm Weber invented probably the first telegraph code, using essentially the same system of 5 binary digits as Bacon. Jean-Maurice-Émile Baudot used the same idea for his Baudot code when he invented his teletypewriter system in 1874. And the Baudot code is the one that Gilbert S. Vernam had in front of him in 1917 when his team at AT&T was asked to investigate the security of teletypewriter communications.

Vernam realized that he could take the string of binary digits produced by the Baudot code and encrypt it by combining each digit from the plaintext with a corresponding digit from the key according to the rules:

0 ⊕ 0 = 0
0 ⊕ 1 = 1
1 ⊕ 0 = 1
1 ⊕ 1 = 0

For example, the digits 10010, which ordinarily represent 18, and the digits 01110, which ordinarily represent 14, would be combined to get:

1 0 0 1 0
0 1 1 1 0


1 1 1 0 0

This gives 11100, which ordinarily represents 28—not the usual sum of 18 and 14.

Some of the systems that AT&T was using were equipped to automatically send messages using a paper tape, which could be punched with holes in 5 columns—a hole indicated a 1 in the Baudot code and no hole indicated a 0. Vernam configured the teletypewriter to combine each digit represented by the plaintext tape to the corresponding digit from a second tape punched with key characters. The resulting ciphertext is sent over the telegraph lines as usual.

At the other end, Bob feeds an identical copy of the tape through the same circuitry. Notice that doing the same operation twice gives you back the original value for each rule:

(0 ⊕ 0) ⊕ 0 = 0 ⊕ 0 = 0
(0 ⊕ 1) ⊕ 1 = 1 ⊕ 1 = 0
(1 ⊕ 0) ⊕ 0 = 1 ⊕ 0 = 1
(1 ⊕ 1) ⊕ 1 = 0 ⊕ 1 = 1

Thus the same operation at Bob’s end cancels out the key, and the teletypewriter can print the plaintext. Vernam’s invention and its further developments became extremely important in modern ciphers such as the ones in Sections 4.3 and 5.2 of The Mathematics of Secrets.

But let’s finish this post by going back to Bacon’s cipher.  I’ve changed it up a little — the covertext below is made up of two different kinds of words, not two different kinds of letters.  Can you figure out the two different kinds and decipher the hidden message?

It’s very important always to understand that students and examiners of cryptography are often confused in considering our Francis Bacon and another Bacon: esteemed Roger. It is easy to address even issues as evidently confusing as one of this nature. It becomes clear when you observe they lived different eras.

Answer to Cipher Challenge #2: Subliminal Channels

Given the hints, a good first assumption is that the ciphertext numbers have to be combined in such a way as to get rid of all of the fractions and give a whole number between 1 and 52.  If you look carefully, you’ll see that 1/5 is always paired with 3/5, 2/5 with 1/5, 3/5 with 4/5, and 4/5 with 2/5.  In each case, twice the first one plus the second one gives you a whole number:

2 × (1/5) + 3/5 = 5/5 = 1
2 × (2/5) + 1/5 = 5/5 = 1
2 × (3/5) + 4/5 = 10/5 = 2
2 × (4/5) + 2/5 = 10/5 = 2

Also, twice the second one minus the first one gives you a whole number:

2 × (3/5) – 1/5 = 5/5 = 1
2 × (1/5) – 2/5 = 0/5 = 0
2 × (4/5) – 3/5 = 5/5 = 1
2 × (2/5) – 4/5 = 0/5 = 0

Applying

to the ciphertext gives the first plaintext:

39 31 45 45 27 33 31 40 47 39 28 31 44 41
 m  e  s  s  a  g  e  n  u  m  b  e  r  o
40 31 35 45 46 34 31 39 31 30 35 47 39
 n  e  i  s  t  h  e  m  e  d  i  u  m

And applying

to the ciphertext gives the second plaintext:

20  8  5 19  5  3 15 14  4 16 12  1  9 14 
 t  h  e  s  e  c  o  n  d  p  l  a  i  n
20  5 24 20  9 19  1 20 12  1 18  7  5
 t  e  x  t  i  s  a  t  l  a  r  g  e

To deduce the encryption process, we have to solve our two equations for C1 and C2.  Subtracting the second equation from twice the first gives:


so

Adding the first equation to twice the second gives:


so

Joshua Holden is professor of mathematics at the Rose-Hulman Institute of Technology.

Bird Fact Friday – Weekly Warbler: Worming-eating

Welcome back to the warblers!

From page 460-461 in The Warbler Guide:

The worm-eating warbler can be identified by its mustard-colored head with four bold black stripes. It has long, pale, and slightly curved bill, and plain, dusky-olive back and wings. The male and female worm-eating warblers look the same in all seasons. The worm-eating warbler is deliberate and acrobatic in its explorations of the understory. It specializes in picking insects from hanging dead leaves.

The Warbler Guide
Tom Stephenson & Scott Whittle
Drawings by Catherine Hamilton
Warbler Guide App
Species Account Example: American Redstart Male

Warblers are amwarblerong the most challenging birds to identify. They exhibit an array of seasonal plumages and have distinctive yet oft-confused calls and songs. The Warbler Guide enables you to quickly identify any of the 56 species of warblers in the United States and Canada. This groundbreaking guide features more than 1,000 stunning color photos, extensive species accounts with multiple viewing angles, and an entirely new system of vocalization analysis that helps you distinguish songs and calls.

The Warbler Guide revolutionizes birdwatching, making warbler identification easier than ever before. For more information, please see the author videos on the Princeton University Press website.

Cipher challenge #2 from Joshua Holden: Subliminal channels

The Mathematics of Secrets by Joshua Holden takes readers on a tour of the mathematics behind cryptography. Most books about cryptography are organized historically, or around how codes and ciphers have been used in government and military intelligence or bank transactions. Holden instead focuses on how mathematical principles underpin the ways that different codes and ciphers operate. Discussing the majority of ancient and modern ciphers currently known, The Mathematics of Secrets sheds light on both code making and code breaking. Over the next few weeks, we’ll be running a series of cipher challenges from Joshua Holden. The first was on Merkle’s puzzles. Today’s focuses on subliminal channels:

As I explain in Section 1.6 of The Mathematics of Secrets, in 1929 Lester Hill invented the first general method for encrypting messages using a set of multiple equations in multiple unknowns.  A less general version, however, had already appeared in 1926, submitted by an 18-year-old to a cryptography column in a detective magazine.  This was Jack Levine, who would later become a prolific researcher in several areas of mathematics, including cryptography.

Levine’s system was billed as a way of encrypting two different messages at the same time.  Maybe one of them was the real message and the other was a dummy message–if the message was intercepted, the interceptor could be thrown off the scent by showing them the dummy message.  This sort of system is now known as a subliminal channel.

The system starts with numbering the letters of the alphabet in two different ways:

   a  b  c  d  e  f  g  h  i  j  k  l  m
  27 28 29 30 31 32 33 34 35 36 37 38 39
   1  2  3  4  5  6  7  8  9 10 11 12 13
  
   n  o  p  q  r  s  t  u  v  w  x  y  z
  40 41 42 43 44 45 46 47 48 49 50 51 52
  14 15 16 17 18 19 20 21 22 23 24 25 26

Suppose the first plaintext, or unencrypted message, is “tuesday” and the second plaintext is “tonight.”  We use the first set of numbers for the first plaintext:

   t  u  e  s  d  a  y
  46 47 31 45 30 27 51

and the second set for the second plaintext:

   t  o  n  i  g  h  t
  20 15 14  9  7  8 20

The encrypted message, or ciphertext, is made up of pairs of numbers.  The first number in each pair is half the sum of the two message numbers, and the second number is half the difference:

    t       u        e       s       d       a        y
   46      47       31      45      30      27       51
  
    t       o        n       i       g       h        t
   20      15       14       9       7       8       20
  
33,13    31,16  22½,8½   27,18 18½,11½  17½,9½  35½,15½

To decrypt the first message, just take the sum of the two numbers in the pair, and to decrypt the second message just take the difference.  This works because if P1 is the first plaintext number and P2 is the second, then the first ciphertext number is

and the second is

Then the plaintext can be recovered from the ciphertext using

and

This system is not as secure as Hill’s because it gives away too much information.  For starters, the existence and nature of the fractions is a clue to the encryption process.  (The editor of the cryptography column suggested doubling the numbers to avoid the fractions, but then the pattern of odd and even numbers would still give information away.)  Also, the first number in each pair is always between 14 and 39 and is always larger than the second number, which is always between ½ and 25 ½.  This suggests that subtraction might be relevant, and the fact that there are twice as many numbers as letters might make a codebreaker suspect the existence of a second message and a second process.  Hill’s system solves some of these issues, but the problem of information leakage continues to be relevant with modern-day ciphers.

With those hints in mind, can you break the cipher used in the following message?

11 3/5, 15 4/5   10 4/5,  9 2/5   17,     11        14 1/5, 16 3/5
 9 4/5,  7 2/5   12 3/5,  7 4/5    9 2/5, 12  1/5   13 1/5, 13 3/5
18,     11       12 2/5, 14 1/5    8 4/5, 10  2/5   12 1/5,  6 3/5
15 4/5, 12 2/5   13 3/5, 13 4/5   12,     16        11 2/5,  8 1/5
 9 1/5, 16 3/5   14,     17       16 3/5, 12  4/5    9 4/5, 14 2/5
12 1/5,  6 3/5   11 3/5, 15 4/5   10,     11        11 4/5,  6 2/5
10 2/5, 14 1/5   17 2/5, 12 1/5   14 3/5,  9  4/5

Once you have the two plaintexts, can you deduce the process used to encrypt them?

 

Answer to Cipher Challenge #1: Merkle’s Puzzles

The hole in the version of Merkle’s puzzles is that the shift we used for encrypting is vulnerable to a known-plaintext attack. That means that if Eve knows the ciphertext and part of the plaintext, she can get the rest of the plaintext. In Cipher Challenge #1, she knew that the word “ten” is part of the plaintext. So she shifts it until she finds a ciphertext that matches one of the puzzles:

ten
UFO
VGP

“Aha!” says Eve. “The first puzzle starts with VGP, so it must decrypt to ten!” Then she decrypts the rest of the puzzle:

VGPVY QUGXG PVYGP VAQPG UKZVG GPUGX GPVGG PBTPU XSNHT JZFEB
whqwz rvhyh qwzhq wbrqh vlawh hqvhy hqwhh qcuqv ytoiu kagfc
xirxa swizi rxair xcsri wmbxi irwiz irxii rdvrw zupjv lbhgd
yjsyb txjaj sybjs ydtsj xncyj jsxja jsyjj sewsx avqkw mcihe
                             ⋮
qbkqt lpbsb kqtbk qvlkb pfuqb bkpbs bkqbb kwokp snico euazw
rclru mqctc lrucl rwmlc qgvrc clqct clrcc lxplq tojdp fvbax
sdmsv nrdud msvdm sxnmd rhwsd dmrdu dmsdd myqmr upkeq gwcby
tentw oseve ntwen tyone sixte ensev entee nzrns vqlfr hxdcz

So the secret key is 2, 7, 21, 16.

The hole can be fixed by using a cipher that is less vulnerable to known-plaintext attacks. Sections 4.4 and 4.5 of The Mathematics of Secrets give examples of ciphers that would be more secure.

Bird Fact Friday—Weekly Warbler: Black-and-White

Welcome back to the warblers!

As we approach the launch of our long-awaited Warbler Guide App for Android, we’re highlighting some fun facts about the warblers with a new Weekly Warbler feature. Kicking it off today is the black and white warbler.

From page 160-161 in The Warbler Guide:

The black-and-white warbler is distinctive in many features. Its black-and-white crown stripes are diagnostic. It has long and slightly curved bill, very broad white supercilium, and contrasty white wing bars joining wide white tertial edgings. Its black-and-white pattern is striking even in flight. It likes to creep on trunks and limbs, and more interestingly, to creep downward. It is the longest-lived warbler on record, at eleven years.

 

The Warbler Guide
Tom Stephenson & Scott Whittle
Drawings by Catherine Hamilton
Warbler Guide App
Species Account Example: American Redstart Male

 

Warblers are amwarblerong the most challenging birds to identify. They exhibit an array of seasonal plumages and have distinctive yet oft-confused calls and songs. The Warbler Guide enables you to quickly identify any of the 56 species of warblers in the United States and Canada. This groundbreaking guide features more than 1,000 stunning color photos, extensive species accounts with multiple viewing angles, and an entirely new system of vocalization analysis that helps you distinguish songs and calls.

The Warbler Guide revolutionizes birdwatching, making warbler identification easier than ever before. For more information, please see the author videos on the Princeton University Press website.

 

Cipher challenge #1 from Joshua Holden: Merkle’s Puzzles

The Mathematics of Secrets by Joshua Holden takes readers on a tour of the mathematics behind cryptography. Most books about cryptography are organized historically, or around how codes and ciphers have been used in government and military intelligence or bank transactions. Holden instead focuses on how mathematical principles underpin the ways that different codes and ciphers operate. Discussing the majority of ancient and modern ciphers currently known, The Mathematics of Secrets sheds light on both code making and code breaking. Over the next few weeks, we’ll be running a series of cipher challenges from Joshua Holden. Presenting the first, on Merkle’s puzzles. 

For over two thousand years, everyone assumed that before Alice and Bob start sending secret messages, they’d need to get together somewhere where an eavesdropper couldn’t overhear them in order to agree on the secret key they would use. In the fall of 1974, Ralph Merkle was an undergraduate at the University of California, Berkeley, and taking a class in computer security. He began wondering if there was a way around the assumption that everyone had always made. Was it possible for Alice to send Bob a message without having them agree on a key beforehand? Systems that do this are now called public-key cryptography, and they are a key ingredient in Internet commerce. Maybe Alice and Bob could agree on a key through some process that the eavesdropper couldn’t understand, even if she could overhear it.

Merkle’s idea, which is now commonly known as Merkle’s puzzles, was slow to be accepted and went through several revisions. Here is the version that was finally published. Alice starts by creating a large number of encrypted messages (the puzzles) and sends them to Bob.

The beginning of Merkle’s puzzles.

Merkle suggested that the encryption should be chosen so that breaking each puzzle by brute force is “tedious, but quite possible.” For our very small example, we will just use a cipher which shifts each letter in the message by a specified number of letters. Here are ten puzzles:

VGPVY QUGXG PVYGP VAQPG UKZVG GPUGX GPVGG PBTPU XSNHT JZFEB
GJBAV ARSVI RFRIR AGRRA GJRYI RFRIR AGRRA VTDHC BMABD QMPUP
AFSPO JOFUF FOUFO TFWFO UXFOU ZGJWF TFWFO UFFOI RCXJQ EHHZF
JIZJI ZNDSO RZIOT ADAOZ ZINZQ ZIOZZ IWOPL KDWJH SEXRJ IKAVV
YBJSY DSNSJ YJJSY BJSYD KNAJX JAJSK TZWXJ AJSYJ JSFNY UZAKM
QCTCL RFPCC RUCLR WDMSP RCCLD GDRCC LQCTC LRCCL JLXUW HAYDT
ADLUA FMVBY ALUVU LVULZ LCLUZ LCLUA LLUGE AMPWB PSEQG IKDSV
JXHUU VYLUJ XHUUJ UDDYD UIULU DJUUD AUTRC SGBOD ALQUS ERDWN
RDUDM SDDMS VDMSX RDUDM SDDMM HMDSD DMRHW SDDMR DUDMS DDMAW
BEMTD MBEMV BGBPZ MMMQO PBMMV AMDMV NQDMA MDMVB MMVUR YCEZC

Alice explains to Bob that each puzzle consists of three sets of numbers. The first number is an ID number to identify the puzzle. The second set of numbers is a secret key from a more secure cipher which Alice and Bob could actually use to communicate. The last number is the same for all puzzles and is a check so that Bob can make sure he has solved the puzzle correctly. Finally, the puzzles are padded with random letters so that they are all the same length, and each puzzle is encrypted by shifting a different number of letters.

Bob picks one of the puzzles at random and solves it by a brute force search. He then sends Alice the ID number encrypted in the puzzle.

Bob solves the puzzle.

For example, if he picked the puzzle on the fifth line above, he might try shifting the letters:

YBJSY DSNSJ YJJSY BJSYD KNAJX JAJSK TZWXJ AJSYJ JSFNY UZAKM
zcktz etotk zkktz cktze lobky kbktl uaxyk bktzk ktgoz vabln
adlua fupul allua dluaf mpclz lclum vbyzl clual luhpa wbcmo
bemvb gvqvm bmmvb emvbg nqdma mdmvn wczam dmvbm mviqb xcdnp

qtbkq vkfkb qbbkq tbkqv cfsbp bsbkc lropb sbkqb bkxfq mrsce
ruclr wlglc rcclr uclrw dgtcq ctcld mspqc tclrc clygr nstdf
svdms xmhmd sddms vdmsx ehudr dudme ntqrd udmsd dmzhs otueg
twent ynine teent wenty fives evenf ourse vente enait puvfh

Now he knows the ID number is “twenty” and the secret key is 19, 25, 7, 4. He sends Alice “twenty”.

Alice has a list of the decrypted puzzles, sorted by ID number:

ID secret key check
zero nineteen ten seven twentyfive seventeen
one one six twenty fifteen seventeen
two nine five seventeen twelve seventeen
three five three ten nine seventeen
seventeen twenty seventeen nineteen sixteen seventeen
twenty nineteen twentyfive seven four seventeen
twentyfour ten one one seven seventeen

So she can also look up the secret key and find that it is 19, 25, 7, 4. Now Alice and Bob both know a secret key to a secure cipher, and they can start sending encrypted messages. (For examples of ciphers they might use, see Sections 1.6, 4.4, and 4.5 of The Mathematics of Secrets.)

Alice and Bob both have the secret key.

Can Eve the eavesdropper figure out the secret key? Let’s see what she has overheard. She has the encryptions of all of the puzzles, and the check number. She doesn’t know which puzzle Bob picked, but she does know that the ID number was “twenty”. And she doesn’t have Alice’s list of decrypted puzzles. It looks like she has to solve all of the puzzles before she can figure out which one Bob picked and get the secret key. This of course is possible, but will take her a lot longer than the procedure took Alice or Bob.

Eve can’t keep up.

Merkle’s puzzles were always a proof of concept — even Merkle knew that they wouldn’t work in practice. Alice and Bob’s advantage over Eve just isn’t large enough. Nevertheless, they had a direct impact on the development of public-key systems that are still very much in use on the Internet, such as the ones in Chapters 7 and 8 of The Mathematics of Secrets.

Actually, the version of Merkle’s puzzles that I’ve given here has a hole in it. The shift cipher has a weakness that lets Eve use Bob’s ID number to figure out which puzzle he solved without solving them herself. Can you use it to find the secret key which goes with ID number “ten”?

Dalton Conley & Jason Fletcher on how genomics is transforming the social sciences

GenomeSocial sciences have long been leery of genetics, but in the past decade, a small but intrepid group of economists, political scientists, and sociologists have harnessed the genomics revolution to paint a more complete picture of human social life. The Genome Factor shows how genomics is transforming the social sciences—and how social scientists are integrating both nature and nurture into a unified, comprehensive understanding of human behavior at both the individual and society-wide levels. The book raises pertinent questions: Can and should we target policies based on genotype? What evidence demonstrates how genes and environments work together to produce socioeconomic outcomes? Recently, The Genome Factor‘s authors, Dalton Conley and Jason Fletcher, answered some questions about their work.

What inspired you to write The Genome Factor?

JF: Our book discusses how findings and theories in genetics and biological sciences have shaped social science inquiry—the theories, methodologies, and interpretations of findings used in economics, sociology, political science, and related disciplines —both historically and in the newer era of molecular genetics. We have witnessed, and participated in, a period of rapid change and cross-pollination between the social and biological sciences. Our book draws out some of the major implications of this cross-pollination—we particularly focus on how new findings in genetics has overturned ideas and theories in the social sciences. We also use a critical eye to evaluate what social scientists and the broader public should believe about the overwhelming number of new findings produced in genetics.

What insights did you learn in writing the book?

JF: Genetics, the human genome project in particular, has been quite successful and influential in the past two decades, but has also experienced major setbacks and is still reeling from years of disappointments and a paradigm shift. There has been a major re-evaluation and resetting of expectations the clarity and power of genetic effects. Only 15 years ago, a main model was on the so-called OGOD model—one gene, one disease. While there are a few important examples where this model works, it has mostly failed. This failure has had wide implications on how genetic analysis is conducted as well as a rethinking of previous results; many of which are now thought to false findings. Now, much analysis is conducted using data 10s or 100s of thousands of people because the thinking is that most disease is caused by tens, hundreds, or even thousands of genes that each have a tiny effect. This shift has major implications for social science as well. It means genetic effects are diffuse and subtle, which makes it challenging to combine genetic and social science research. Genetics has also shifted from a science of mechanistic understanding to a large scale data mining enterprises. As social scientists, this approach is in opposition to our norms of producing evidence. This is something we will need to struggle through in the future.

How did you select the topics for the book chapters?

JF: We wanted to tackle big topics across multiple disciplines. We discuss some of the recent history of combining genetics and social science, before the molecular revolution when “genetics” were inferred from family relationships rather than measured directly. We then pivot to provide examples of cutting edge research in economics and sociology that has incorporated genetics to push social science inquiry forward. One example is the use of population genetic changes as a determinant of levels of economic development across the world. We also focus our attention to the near future and discuss how policy decisions may be affected by the inclusion of genetic data into social science and policy analysis. Can and should we target policies based on genotype? What evidence do we have that demonstrates how genes and environments work together to produce socioeconomic outcomes?

What impact do you hope The Genome Factor will have?

JF: We hope that readers see the promise as well as the perils of combining genetic and social science analysis. We provide a lot of examples of ongoing work, but also want to show the reader how we think about the larger issues that will remain as genetics progresses. We seek to show the reader how to look through a social science lens when thinking about genetic discoveries. This is a rapidly advancing field, so the particular examples we discuss will be out of date soon, but we want our broader ideas and lens to have longer staying power. As an example, advances in gene editing (CRISPR) have the potential to fundamentally transform genetic analysis. We discuss these gene editing discoveries in the context of some of their likely social impacts.

Dalton Conley is the Henry Putnam University Professor of Sociology at Princeton University. His many books include Parentology: Everything You Wanted to Know about the Science of Raising Children but Were Too Exhausted to Ask. He lives in New York City. Jason Fletcher is Professor of Public Affairs, Sociology, Agricultural and Applied Economics, and Population Health Sciences at the University of Wisconsin–Madison. He lives in Madison. They are the authors of The Genome Factor: What the Social Genomics Revolution Reveals about Ourselves, Our History, and the Future.