🔖 ❤️ OnlineCrsLady tweeted in his cryptography/blockchain talk for #Domains19 @poritzj mentioned steganography, so I wanted to share with him, plus with anyone interested in such weirdness, the Latin Steganometrographia for creating cryptographic poetry in Latin: cool, bizarre, fun! https://t.co/5JawIqhbQF https://t.co/jqnJPJZcwh

Bookmarked a tweet by Laura GibbsLaura Gibbs (Twitter)

🔖 Yet Another Introductory Number Theory Textbook (Cryptology Emphasis Version)

Bookmarked Yet Another Introductory Number Theory Textbook (Cryptology Emphasis Version) by Jonathan A. Poritz (poritz.net)

Preface This is a first draft of a free (as in speech, not as in beer) (although it is free as in beer as well) undergraduate number theory textbook. It was used for Math 319 at Colorado State University – Pueblo in the spring semester of 2014. Thanks are hereby offered to the students in that class — Megan Bissell, Tennille Candelaria, Ariana Carlyle, Michael Degraw, Daniel Fisher, Aaron Griffin, Lindsay Harder, Graham Harper, Helen Huang, Daniel Nichols, and Arika Waldrep — who offered many useful suggestions and found numerous typos. I am also grateful to the students in my Math 242 Introduction to Mathematical Programming class in that same spring semester of 2014 — Stephen Ciruli, Jamen Cox, Graham Harper, Joel Kienitz, Matthew Klamm, Christopher Martin, Corey Sullinger, James Todd, and Shelby Whalen — whose various programming projects produced code that I adapted to make some of the figures and examples in the text.

The author gratefully acknowledges the work An Introductory Course in Elementary Number Theory by Wissam Raji [see www.saylor.org/books/] from which this was initially adapted. Raji's text was released under the Creative Commons CC BY 3.0 license, see creativecommons.org/licenses/by/3.0. This work is instead released under a CC BY-SA 4.0 license, see creativecommons.org/licenses/by-sa/4.0. (The difference is that if you build future works off of this one, you must also release your derivative works with a license that allows further remixes over which you have no control.)

  • Available for download and remix, under a Creative Commons CC BY-SA 4.0 licence. First used for Math 319: Number Theory at Colorado State University-Pueblo in the spring of 2014.
  • pdf — 864K
  • source code can be found here
  • You can buy a physical copy, if that's your thing, from the on-demand printing service Lulu at this link for $6 (plus shipping and handling). [I make 61¢ profit for each such sale: I'm happy to reimburse you that amount if you will personally contact me.]

via: https://www.poritz.net/jonathan/share/index.html

Hat tip:

👓 Is Secret sharing REALLY REALLY REALLY used? | Computational Complexity

Read Is Secret sharing REALLY REALLY REALLY used? (blog.computationalcomplexity.org)
Since I am teaching Cryptography this semester I am teaching things people REALLY REALLY REALLY (RRR) use. For some topics this is RRR true,...

I like this concept of Really, Really, Really used. Reminds me of the value of finding use cases for markup like microformats in the wild as a means of standardizing things or for paving cow paths.

👓 The World’s Oldest Blockchain Has Been Hiding in the New York Times Since 1995 | Motherboard | Vice

Read The World’s Oldest Blockchain Has Been Hiding in the New York Times Since 1995 (Motherboard)
This really gives a new meaning to the “paper of record."

👓 Gravatar Advisory: How to Protect Your Email Address and Identity | Wordfence

Read Gravatar Advisory: How to Protect Your Email Address and Identity (Wordfence)
Update: We’ve added comments at the end of the post pointing out that the National Institute of Standards and Technology (NIST) considers an email address to be personally identifiable information or PII. Gravatar is a service that provides users with a profile image that can appear on many sites across the Net. It is integrated with …

👓 Hiding Information in Plain Text | Spectrum IEEE

Read Hiding Information in Plain Text (IEEE Spectrum: Technology, Engineering, and Science News)
Subtle changes to letter shapes can embed messages

An interesting piece to be sure, but I’ve thought of doing this sort of steganography in the past. In particular, I recall having conversations with Sol Golomb about similar techniques in the past. I’m sure there’s got to be prior art for similar things as well.

🎞 The Imitation Game (2014)

Watched The Imitation Game from The Weinstein Company
Directed by Morten Tyldum. With Benedict Cumberbatch, Keira Knightley, Matthew Goode, Allen Leech. During World War II, the English mathematical genius Alan Turing tries to crack the German Enigma code with help from fellow mathematicians.

Sometimes it’s the very people who no one imagines anything of who do the things no one can imagine.

–an interesting sentiment repeated through the film

I think this was one of the most interesting moments in the film with a very interesting double entedre:

Of course machines can’t think as people do. A machine is different from a person. Hence, they think differently. The interesting question is, just because something, uh… thinks differently from you, does that mean it’s not thinking? Well, we allow for humans to have such divergences from one another. You like strawberries, I hate ice-skating, you cry at sad films, I am allergic to pollen. What is the point of… different tastes, different… preferences, if not, to say that our brains work differently, that we think differently? And if we can say that about one another, then why can’t we say the same thing for brains… built of copper and wire, steel?

I was a bit worried that this film would miss out on one or two crucial technical details that the wider audience should be at least be made aware. It succeeded in presenting all of them, including the concept of a telegraphic “hand”.

The exertion scenes of Alan running were a bit too on-the-nose for me as a proxy for his mental effort and work, particularly given the rest of the general tenor of his character. It was an interesting cinematic and emotional trick however.

This was an incredibly well put together film. I was far more impressed than I had expected to be.

Watched on Netflix


👓 Technology preview: Private contact discovery for Signal | Signal

Read Technology preview: Private contact discovery for Signal by moxie0 (Signal)
At Signal, we’ve been thinking about the difficulty of private contact discovery for a long time. We’ve been working on strategies to improve our current design, and today we’ve published a new private contact discovery service. Using this service, Signal clients will be able to efficiently and scalably determine whether the contacts in their address book are Signal users without revealing the contacts in their address book to the Signal service.

There’s a lot of work involved here, but this is an intriguing proposition for doing contact discovery in social media while maintaining privacy. I can’t wait to see which silos follow suit, but I’m even more curious if any adventurous IndieWeb creators will travel down this road?

h/t cryptographer Matthew Green

The Web Cryptography API is a W3C Recommendation | W3C News

Bookmarked The Web Cryptography API is a W3C Recommendation (W3C News)
The Web Cryptography Working Group has published a W3C Recommendation of the Web Cryptography API. This specification describes a JavaScript API for performing basic cryptographic operations in web applications, such as hashing, signature generation and verification, and encryption and decryption. Additionally, it describes an API for applications to generate and/or manage the keying material necessary to perform these operations. Uses for this API range from user or service authentication, document or code signing, and the confidentiality and integrity of communications.


Primes as a Service on Twitter

Our friend Andrew Eckford has spent some time over the holiday improving his Twitter bot Primes as a Service. He launched it in late Spring of 2016, but has added some new functionality over the holidays. It can be relatively handy if you need a quick answer during a class, taking an exam(?!), to settle a bet at a mathematics tea, while livetweeting a conference, or are hacking into your favorite cryptosystems.

General Instructions

Tweet a positive 9-digit (or smaller) integer at @PrimesAsAService. It will reply via Twitter to tell you if the number prime or not.

Some of the usable commands one can tweet to the bot for answers follow. (Hint: Click on the buttons with the tweet text to auto-generate the relevant Tweet.)

If you ask about a prime number with a twin prime, it should provide the twin.

Pro tip: You should be able to drag and drop any of the buttons above to your bookmark bar for easy access/use in the future.

Happy prime tweeting!