FYI. As I understand it, TI calculator boot ROMs use a 512 bit RSA public key to check the signature of the software they're loading. When hobbyists who wanted to run their own alternative OS software on their calculator calculated the corresponding private key and were thus able to sign their own software, TI sent them DMCA takedowns claiming they had cracked TI's DRM. As with the CSS keys, a publish/takedown chase ensued. Wikileaks has had the censored keys up since August. EFF is now representing the hobbyists, and may stand to collect legal fees from TI. Here's Schneier's take:
http://www.schneier.com/blog/archives/2009/09/texas_instrumen.html John Electronic Frontier Foundation Media Release For Immediate Release: Tuesday, October 13, 2009 Contact: Jennifer Stisa Granick Civil Liberties Director Electronic Frontier Foundation jenni...@eff.org +1 415 436-9333 x134 EFF Warns Texas Instruments to Stop Harassing Calculator Hobbyists Baseless Legal Threats Squash Free Speech, Innovation San Francisco - The Electronic Frontier Foundation (EFF) warned Texas Instruments (TI) today not to pursue its baseless legal threats against calculator hobbyists who blogged about potential modifications to the company's programmable graphing calculators. TI's calculators perform a "signature check" that allows only approved operating systems to be loaded onto the hardware. But researchers were able to reverse-engineer signing keys, allowing tinkers to install custom operating systems and unlock new functionality in the calculators' hardware. In response to this discovery, TI unleashed a torrent of demand letters claiming that the anti-circumvention provisions of the Digital Millennium Copyright Act (DMCA) required the hobbyists to take down commentary about and links to the keys. EFF represents three men who received such letters. "The DMCA should not be abused to censor online discussion by people who are behaving perfectly legally," said Tom Cross, who blogs at memestreams.net. "It's legal to engage in reverse engineering, and its legal to talk about reverse engineering." In fact, the DMCA explicitly allows reverse engineering to create interoperable custom software like the programs the hobbyists are using. Additionally, TI makes its software freely available on its website, so there is no connection between the use of the keys and unauthorized distribution of the code. "This is not about copyright infringement. This is about running your own software on your own device -- a calculator you legally bought," said EFF Civil Liberties Director Jennifer Granick. "Yet TI still issued empty legal threats in an attempt to shut down discussion of this legitimate tinkering. Hobbyists are taking their own tools and making them better, in the best tradition of American innovation." For the full letters sent to Texas Instruments by EFF on behalf of their clients: http://www.eff.org/files/filenode/coders/TI%20Claim%20Ltr%20101309.pdf For this release: http://www.eff.org/press/archives/2009/10/13 About EFF The Electronic Frontier Foundation is the leading civil liberties organization working to protect rights in the digital world. Founded in 1990, EFF actively encourages and challenges industry and government to support free expression and privacy online. EFF is a member-supported organization and maintains one of the most linked-to websites in the world at http://www.eff.org/ -end- --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to majord...@metzdowd.com