tag:blogger.com,1999:blog-37798047.post2126219933757573011..comments2024-01-16T05:48:33.523-05:00Comments on Errata Security: Why the crypto-backdoor side is morally corruptDavid Maynorhttp://www.blogger.com/profile/09921229607193067441noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-37798047.post-52323085798207034762018-04-02T22:04:50.850-04:002018-04-02T22:04:50.850-04:00The core argument as I understand it is "effo...The core argument as I understand it is "efforts to provide law enforcement with crypto-backdoors will harm your security."<br /><br />That's simply not true and past experience has taught us on two different occasions that efforts to provide law enforcement with some secret key/mechanism can counter-intuitively <b>improve</b> security. <br /><br />The clipper chip is cited to the point of cliché but a direct consequence of its failure was loosening of export regulations which meant everyone could implement secure cryptography protocols, not just those inside of the US. A clear case where an effort to provide law enforcement with a backdoor resulted in an improvement.<br /><br />Less well known is the origin story behind the Diffie-Hellman-Merkle key exchange. Back in 1973 virtually all cryptography was symmetric. Public-Private key systems just weren't a thing yet. Keys needed to be manually exchanged through tedious methods. Hellman sought to create a scheme that let you programmatically create crypto-backdoors in <i>symmetric ciphers</i>. A meta cipher that ensured you could create a secret key (x2) to decipher exchanges encrypted with a secret primary key (x1). A scheme where ciphers setup to use (x1) to encrypt and decrypt messages could secretly be decrypted by law-enforcement using (x2). It wasn't until they built this thing and had it up and running that they realized they could flip this model on its head and recognized a neat side-effect if you didn't keep (x2) secret at all. Instead by publically exchanging (x2) in the clear one could use it to provide a means for secure private key generation without sending the key over the wire. Again an effort to produce a crypto-backdoor system that resulted in an improvement in security.<br /><br />They calculated the cost of breaking an existing 50-bit DES key at somewhere between $10,000-$100,000 in 1970's compute power - but with their new scheme they could rotate keys on a regular enough basis to make this attack mitigable and a crucial step along with the development of RSA around the same time.<br /><br />I don't disagree that the parties advocating for backdoors in earnest aren't morally bankrupt, nor that all efforts here won't have negative consequences, just that two important improvements exist as a contradiction to the central premise of this argument that research or political movements here bare no fruit.Anonymoushttps://www.blogger.com/profile/10343733907246583795noreply@blogger.com