Tech Teaching

Cryptosmith Video Series #1 through #15

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Diagram of signing a public-key certificateI have posted the fifteenth video in the Cryptosmith Series on practical basic cryptography. The video collection falls into three parts: the network crypto introduction, the DVD example, and the public-key certificate discussion.

There are also updates to other series videos. They now use the acronym “SSL” a lot more, since people recognize it more often than “TLS.” The public-key discussions now include elliptic curve algorithms, since they are very popular in state-of-the-art SSL (TLS) deployments.

An overview and notes about the series appear below. If you take the time to look at these videos, please “like” and/or comment as appropriate.

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Security

Cryptosmith Video Series

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Banner for Transport Layer Security videoThe Cryptosmith video series uses animation to explain well-known crypto techniques. This should help more people understand crypto technology. This is particularly important as people rely more and more on mobile and Internet security mechanisms. Aside from protecting online commerce and financial activities, many professionals are realizing that their daily activities require strong protection.

[UPDATE: See the latest post to summarize the video series.]

After publishing three books on cybersecurity and cryptography I’m looking for a different medium for explaining technical concepts. While there are many online tutorial videos, most are narrated slide presentations. I’m trying something else.

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Security

#PodestaEmails are NOT obvious fakes

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Wikileaks globe-hourglass logoEmails are notoriously hard to validate. Emails are like typed, signed contracts with no section or page numbers: you can take out or add whatever pages you want as long as you keep the signatures.

Intelligence expert Malcom Nance has tweeted that Wikileaks’ recent collection of Podesta emails contain “obvious forgeries.” It is hard to detect emails forgeries in general, but easy to find obvious forgeries. For details, check out Chapter 15 of Elementary Information Security, my textbook.

I searched recent news reports highlighting specific Podesta emails. I looked at about a dozen of those emails, plus similar “unimportant” emails. I checked the email delivery data for tampering or forgery. The email headers look correct. Thus there are no “obvious forgeries.”

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Security

Election Crypto Conspiracy Theory

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Eye atop a pyramid - a mystical signI’m not often a fan of conspiracy theories, except for entertainment value. This one is interesting because it combines international intrigue, the elections, and our world of notoriously poor email security.

The conspiracy arises from foreigners trying to influence the United States election. They spy on unprotected emails and leak the contents to influence US public opinion. This isn’t limited to attacks on the Democratic candidate Hillary Clinton. Some suggest that Fox News and the Trump campaign have also been attacked this way.

We could be blocking this threat, except that pressure groups within the government want to leave as much information unprotected as possible, notably law enforcement and intelligence agencies. I think we face a greater threat from foreign exploitation of our unprotected emails than we face from impeded investigations or even a few terrorist bombs.

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Tech History

A Yank at Bletchley Park

A friend and colOne of Turing's Bombe devicesleague introduced me to a 94-year-old gentleman with a rare tale to tell. John McCallister was recruited during World War II to be a US Army liaison officer at “Station X,” the UK’s highly secret codebreaking operation at Bletchley Park. Station X collected intercepted German radio messages, all encrypted with the supposedly-unbreakable Enigma cipher, and broke the encryption. The resulting data was distributed to a handful of senior UK and US military commanders.

At first, McCallister worked at Bletchley and learned about the codebreaking operation. He met Alan Turing, now recognized as a giant in computer science. Turing developed codebreaking machines at Bletchley, including the “bombe” (left). Then McCallister prepared for his own role: to handle and distribute the highly secret information to senior US military commanders.

Following the war, McCallister left the crypto world. After college and reserve service for the Korean War, he applied his mathematic skills to business accounting at General Electric and Zenith Electronics. He retired in 1984.

[Postscript added]

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Security

Symantec Breaks Trust with the Internet?

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Crypto machine rotor

Symantec is one of the companies that holds the keys to the Internet: they are a trusted certificate authority for authenticating major web sites. All major browsers recognize Symantec as a trustworthy source of SSL/TLS authentication certificates. Symantec (also known by its subsidiary name Verisign) is part of a chain of trust that keeps our Internet traffic safe.

Recent reports suggest that they have broken their trust with the Internet community. Symantec has apparently delegated some of its authentication authority to Blue Coat software, a company that makes and sells network snooping gear. A 2013 report by Reporters Without Borders contains 2 pages highlighting Blue Coat’s role in helping repressive regimes monitor encrypted web traffic.

Symantec has issued Blue Coat its own authority certificate. Blue Coat can use this to create and distribute bogus certificates that allow its gear to decrypt encrypted web traffic.

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Security

Update on the Apple Music Mess

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The trouble reported earlier with Apple Music seems to have attracted high level attention. James Pinkstone had reported that Apple Music deleted countless unique tracks he had stored in iTunes, and that an Apple service rep assured him this was correct behavior.

As he describes in a later blog post, Apple contacted him promptly. They assured him that file deletion is not an intended feature of Apple Music, and they sent engineers to try to figure it out.

This doesn’t change my own conclusion: the only way to ensure ownership of electronic media is to remove copy protection. This requires a bit of geeking around on a desktop. If your ebooks and music reside exclusively in proprietary apps, like Kindle or the Apple products, then the vendor can delete them at will. It happened on the Kindle.

Tech History

Which cables to keep, which to discard?

Serial cable vs parallel cableCNET recently published a list of cables to keep and cables to discard. I like to keep things for historical interest as well as for practical reasons. Historical examples allow me to show students different ways of doing the same thing. The picture on the left illustrates “serial vs parallel” and I use a similar image in my textbook. I don’t collect ancient types of wire for investment purposes: values don’t justify it.

You need to decide why you want to keep cables, and keep the cables accordingly. Like most Web journalism, CNET largely ignored that question. Here are some reasons:

  • I have equipment that uses a particular cable
  • I’ll probably buy equipment that uses a particular cable.

Let’s look at those reasons and consider CNET’s recommendations.

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