Security quotes of the week

To address this type of attacker, we present Oblivious DNS (ODNS), which is a new design of the DNS ecosystem that allows current DNS servers to remain unchanged and increases privacy for data in motion and at rest. In the ODNS system, both the client is modified with a local resolver, and there is a new authoritative name server for .odns. To prevent an eavesdropper from learning information, the DNS query must be encrypted; the client generates a request for www.foo.com, generates a session key k, encrypts the requested domain, and appends the TLD domain .odns, resulting in {www.foo.com}k.odns. The client forwards this, with the session key encrypted under the .odns authoritative server’s public key ({k}PK) in the “Additional Information” record of the DNS query to the recursive resolver, which then forwards it to the authoritative name server for .odns. The authoritative server decrypts the session key with his private key, and then subsequently decrypts the requested domain with the session key. The authoritative server then forwards the DNS request to the appropriate name server, acting as a recursive resolver. While the name servers see incoming DNS requests, they do not know which clients they are coming from; additionally, an eavesdropper cannot connect a client with her corresponding DNS queries.

Up till now, writers of crypto and security software not only have to fight the bad guys. We also have to deal with compiler writers, who every so often dream up some new optimisation routine which spots the padding instructions that we put in to make our crypto algorithms run in constant time, or the tricks that we use to ensure that sensitive data will be zeroised when a function returns. All of a sudden some critical code is optimised away, your code is insecure, and you scramble to figure out how to outwit the compiler once more.

So while you’re fighting the enemy in front, the compiler writer is a subversive fifth column in your rear.

Last year, the Defcon hackers' conference sponsored [PDF] a Voting Village. Organizers collected 25 pieces of voting equipment, including voting machines and electronic poll books. By the end of the weekend, conference attendees had found ways to compromise every piece of test equipment: to load malicious software, compromise vote tallies and audit logs, or cause equipment to fail.

It's important to understand that these were not well-funded nation-state attackers. These were not even academics who had been studying the problem for weeks. These were bored hackers, with no experience with voting machines, playing around between parties one weekend.

    int slow(int i, int j) __attribute__((noinline,optimize("0")));