Category Archives: Cryptography

Thoughts on Snowden’s Dead Man’s Switch

It would have been more morally pure for Snowden to choose to stay home and face the consequences after his act of civil disobedience.

I don’t think it follows, however, that Snowden is acting irrationally or treasonously or (wrongly) “taking a hostage” by setting up (or claiming to set up) an information-disclosure insurance policy against reprisals by the US. For evidence for this proposition one need look no further than the very eloquent NYT op-ed by Nasser al-Awlaki, The Drone That Killed My Grandson. Remember that we now live in a country that has a track record of executing US citizens (so-called “targeted killing”) without trial, at least outside the US. The limiting principle, we are told, is that the US only does this when it considers them a grave threat, and cannot get hold of them any other way because they are beyond the reach of arrest — not principles likely to be of great comfort to a Snowden.

For a cryptographer’s analysis of this tactic, see Bruce Schneier’s, Snowden’s Dead Man’s Switch. Schneier suggests it may be counter-productive:

I’m not sure he’s thought this through, though. I would be more worried that someone would kill me in order to get the documents released than I would be that someone would kill me to prevent the documents from being released. Any real-world situation involves multiple adversaries, and it’s important to keep all of them in mind when designing a security system.

A commentator counters that in fact this creates a different incentive:

If the US does not want these secrets released then it is in their interests to keep him alive.

It’s also makes it more imperative to capture him in case anyone else kills him.

Posted in Cryptography, Law: Criminal Law, National Security, Padilla | 2 Comments

Paranoids Really Do Have Enemies

Use of Tor and e-mail crypto could increase chances that NSA keeps your data | Ars Technica

Update: For the point of view that all is well, except for the fact of the leaks, see Stewart Baker, But Enough About You …. Note that to read this post in its true context you need to understand what it means for the NSA to decide a post might be foreign in some way. A good place to start might be Ed Felton’s 51% foreign test doesn’t protect Americans.

Posted in Cryptography | 1 Comment

EFF Is Accepting Bitcoins Again

EFF Will Accept Bitcoins to Support Digital Liberty. This follows a 2-year moratorium.

One key difference from past practice: EFF will liquidate any Bitcoins it receives as soon as it gets them.

EFF’s announcement pointed me to this recent (March 18, 2013) Fincen guidance document, Application of FinCEN’s Regulations to Persons Administering, Exchanging, or Using Virtual Currencies which I had missed. Key graph:

A user who obtains convertible virtual currency and uses it to purchase real or virtual goods or services is not an MSB [Money Services Businesses] under FinCEN’s regulations. Such activity, in and of itself, does not fit within the definition of “money transmission services” and therefore is not subject to FinCEN’s registration, reporting, and recordkeeping regulations for MSBs.

Posted in Cryptography, Econ & Money | Leave a comment

Big Brother is WWWatching You (feat. George Orwell)

Rap News 15:

Good stuff! Lots of cute in-jokes too.

Spotted via BoingBoing.

Posted in Civil Liberties, Cryptography, Internet, Law: Privacy | Leave a comment

Checking In With Bitcoin (2)

Hacker steals $250k in Bitcoins from online exchange Bitfloor | Ars Technica

The future of the up-and-coming Bitcoin exchange Bitfloor was thrown into question Tuesday when the company’s founder reported that someone had compromised his servers and made off with about 24,000 Bitcoins, worth almost a quarter-million dollars. The exchange no longer has enough cash to cover all of its deposits, and it has suspended its operations while it considers its options.

This comes on the heels of news of the collapse of what’s been called a giant Bitcoin Ponzi scheme. See Official: Bitcoin Loan Shark ‘pirateat40′ Defaults for details:

A mountain of problems have been growing the past several weeks surrounding the recent drama around massive Bitcoin lender, pirateat40, as reports of fund inaccessibility came out of the wood work.

Purported to have had somewhere around 500,000 BTC in Bitcoin Savings & Trust, his fund that was offering deposit account holders up to 7% weekly interest on their holdings. The lending service provider announced a default on borrowed assets just a short while ago; the estimated value for the defaulted assets is $5,000,000 USD.

Actually, the amazing part is that Bitcoin isn’t totally dead.

Previously: Bitcoin & Gresham’s Law & Botnets (2/22/12); Checking In With Bitcoin (10/25/11) and Why Bitcoin Isn’t As Exciting as it May Sound (6/11/11).

Posted in Cryptography, Econ & Money | Leave a comment

Key Cryptography Concept Explained

I thought this video explanation of Public Key Cryptography: Diffie-Hellman Key Exchange [or, if you prefer, Diffie-Hellman-Merkle key exchange] was unusually clear. Secure key exchange is really important, because exchanging keys securely with someone is an essential prerequisite to creating a secure communications channel with them.

This video is great for people who want an intro to one of the central ideas in modern cryptography:

OK, there was a little math in there, but not so much.

Posted in Cryptography | 1 Comment

EFF Announces Coders’ Rights List

EFF has a new mailing list devoted to “the latest news on computer security law, upcoming events with EFF lawyers, discounts on infosec conferences like BlackHat, SOURCE, HOPE, and open source software events.” Sign me up.

There’s a wacky promo which I think someone had too much fun making:

Disclosure: I am on the EFF Advisory Board.

Posted in Civil Liberties, Cryptography, Internet | Leave a comment