Cryptosmith Institute

Teaching with Design Principles

Design principles help students learn the essentials of technical design tasks. Students apply simple-sounding rules to achieve desired design features. The trick is to present students with design principles they can see in real life, understand, and apply in their own efforts. Here are my observations on how to write design principles to teach technical design. Many cybersecurity textbooks discuss…...

Teaching with Design Principles Design principles help students learn the essentials of technical design tasks. Students apply simple-sounding rules to achieve desired design features. The trick is to present students with design…

This is a short, gentle two-part introduction to basic cryptographic concepts using text-based crypto examples. Illustrates encryption, decryption, ciphers, keys, algorithms, code cracking, cryptanalysis, and letter frequency analysis. Full disclosure: I produced these videos over a decade ago. Now they are hosted directly on this web site as opposed to elsewhere. Here is a PDF built from the animated slide decks: …...

Grade School Crypto Videos This is a short, gentle two-part introduction to basic cryptographic concepts using text-based crypto examples. Illustrates encryption, decryption, ciphers, keys, algorithms, code cracking, cryptan…

I found this in my files. I no doubt intended to publish it months ago and forgot to finish it and press the button. Senior government officials traditionally restrict defense-related conversations to special locations to prevent eavesdropping. The most secret conversations occur in places like the White House Situation Room or protected command centers in military sites. The officials also declare the conversation to be…...

Why Signalgate Matters I found this in my files. I no doubt intended to publish it months ago and forgot to finish it and press the button. Senior government officials traditionally restrict defense-related conversations…

A person called me on the phone a few moments ago claiming to be from US Bank. He said there was some fraud detected on my account: someone created a new checking account with my identity information. "So, you have my identity information?" I asked. "Yes," he replied. "Can you prove who you say you are?" I got the first 3 words out before he abruptly hung up....

Another Telephone Phish A person called me on the phone a few moments ago claiming to be from US Bank. He said there was some fraud detected on my account: someone created a new checking account with my identity informati…

Quantum codebreaking uses a theoretically "large" quantum computer codebreaking. Today, quantum computers handle very tiny numbers. The most impressive examples deal with numbers less than 22. In theory, a “large" quantum computer could quickly crack codes we use every day to protect data. I’ve been skeptical about quantum codebreaking for decades. I think it violates physical laws like conservation of energy....

Making Fun of Quantum Codebreaking Quantum codebreaking uses a theoretically “large” quantum computer codebreaking. Today, quantum computers handle very tiny numbers. The most impressive examples deal with numbers less t…

"Johnny" von Neumann was a mid-century giant in math and a respected advisor to the US government. On May 15, 1946, he gave a talk to the Mathematical Computing Advisory Panel of the Office of Naval Research and Inventions titled "The Principles of Large Scale Computing Machines."1 A year earlier von Neumann had scooped Eckert and Mauchly, developers of the pioneering ENIAC computer, by publishing…...

Von Neumann Talks to the Navy “Johnny” von Neumann was a mid-century giant in math and a respected advisor to the US government. On May 15, 1946, he gave a talk to the Mathematical Computing Advisory Panel of the Of…

Journalists aren't usually invited to online chats about US war plans. This seemed obvious until yesterday, when Atlantic editor Jeffrey Goldberg published his article about being a lurker in an online chat with US Secretaries of State, Defense, and Treasury, plus the VP and the Director of National Intelligence. The plans led to a US attack against Houthi rebels in Yemen…...

War Plan Chat Includes Journalist Journalists aren’t usually invited to online chats about US war plans. This seemed obvious until yesterday, when Atlantic editor Jeffrey Goldberg published his article about being a lurker in…

Do not call that number! This attack is brilliant. It uses a legitimate PayPal email message about a bogus payment to trick you into phoning a bogus PayPal phone number. I have received several of them this week with various names for the company sending the money request. Different emails contain different subjects and different phone numbers to call. All went to an email address probably scraped off the Web....

Clever PayPal-based Attack Do not call that number! This attack is brilliant. It uses a legitimate PayPal email message about a bogus payment to trick you into phoning a bogus PayPal phone number. I have received several of …

Here is a set of geographical maps of the ARPANET in the 1970s and 1980s. There is also one "logical" map that focuses more on which host computers were connected where. The ARPANET was a precursor (some would say "the precursor") to today's Internet. It pioneered transcontinental and transoceanic digital networking, adaptive routing, modern email, and many fundamental concepts of flexible, fault-tolerant digital data transmission....

ARPANET Maps Here is a set of geographical maps of the ARPANET in the 1970s and 1980s. There is also one “logical” map that focuses more on which host computers were connected where. The ARPANET was…

It was only a matter of time before someone did this. Bitlocker is Microsoft's technique for encrypting a desktop, laptop, or other MS Windows device. We encrypt the device to protect the contents if it is ever stolen. In theory, the only way Windows will start up if it is Bitlocked (is that really a word?) is by entering the right password when it boots....

Breaking Bitlocker It was only a matter of time before someone did this. Bitlocker is Microsoft’s technique for encrypting a desktop, laptop, or other MS Windows device. We encrypt the device to protect the con…

A clever person has hosted a Password Game. Give it a try!

Play the Password Game! A clever person has hosted a Password Game. Give it a try!

Here is a classic example of human nature: people on a gaming site argue that the site's tanks don't accurately reflect their capabilities. Participants post classified information to prove their point. Reporters have been following this story for almost a year on the game War Thunder. The first case appeared a couple summers ago regarding Britain's Challenger 2 tank…...

Leaking Secrets Under Social Pressure Here is a classic example of human nature: people on a gaming site argue that the site’s tanks don’t accurately reflect their capabilities. Participants post classified information to p…