Working on my presentation [SOOC]

As noted in an earlier post, I’m giving a presentation on Bitcoin and cryptocurrency to a local group of retirees. The 5-session outline:
     1. “Money”: Definitions; “types” of money; a brief history
     2. Cash, digital transactions and tracing transfers
     3. Transaction security in an online world
     4. Bitcoin and “blockchains”: Motivations, design, & problems
     5. Wrap-up: Software wallets, decentralization; Q and hopefully-A?
Note: A 365 post made class #2 because selling that craft was a cash transaction.

The fanned-out deck of cards is part of session 3, “Transaction security in an online world.” “How’s that,” you ask? It turns out, as many magicians know, eight “perfect shuffles” of a deck of cards will return the deck to its original order. » Sure, I’ll wait while you Google perfect shuffle.

Although it looks like I made a mistake, in the image above, I am three perfect shuffles into a deck of cards that were in original order when I started. Notice the order: sixes and Queens are together (alternating), then fives and Jacks, then fours and tens. And so it goes.

Note: After two perfect shuffles, all ranks are together: the four Aces, then the four Kings, then the four Queens, and so on. I could send you a spreadsheet where the order is worked out after each shuffle…

So what does this have to do with Bitcoin and cryptocurrency? Strong encryption. I first learned about the cycling of perfect shuffles reading Marcus du Sautoy’s The Music of the Primes about RSA encryption. The mathematics of encryption and decryption systems was the hook that drew me into agreeing to creating a Bitcoin-and-cryptocurrency presentation. :)

[ PXL_20220313_030859741.PORTRAIT :: cell phone ]

Looking back
  1 year ago: “Pandemic Puzzle #33”
 2 years ago: No post
 3 years ago: “Broken by Kyle [Filler]”
 4 years ago: “$150 nail”
 5 years ago: No post
 6 years ago: “Thinking of our dads…” (Or: how many screwdrivers does one need?)
 7 years ago: “Lagerstroemia fruit (loculicidal capsule)”
 8 years ago: “Plumbago auriculata (“Cape leadwort”)”
 9 years ago: “It was a one-shot day”
10 years ago: “Abstract in Blue”
11 years ago: “Spiroaira”

[GaryW]

Interesting! I'd love to hear your presentation!

[Thom Mitchell]

@thewatersphotos The sessions weren't recorded and stored anywhere, but I could email any/all .pdf file(s)
1. “Money”: Definitions; “types” of money; a brief history, 2.36Mb
2. Cash, digital transactions & tracing transfers, 1.78Mb
3. Transaction security in an online world, 2.86Mb
4. Bitcoin and “blockchains”: Motivations, design, & problems, 4.29Mb
5. Wallets, decentralization; wrap-up; Q and hopefully-A?, 1.79Mb
My email: tmitch [at] siu [dot] edu.

I searched to see if my email is publicly searchable any longer and it seems it is not. However, an ages-old (16½ years!) news item about my undergraduate class is still online, https://news.siu.edu/2006/11/110106sm6139.php

[Thom Mitchell]

@dutchothotmailcom Thought about your son as I was posting this…