Tag Archives: DDoS

NTP Filtering (Delay & Blockage) in the Internet

NTP (Network Time Protocol) messages are sometimes rate-limited or blocked entirely by Internet operators. This little-known “NTP filtering” was put into place several years ago in response to DDoS (Distributed Denial of Service) attacks. NTP filtering may drop NTP messages based on rate or message size. Let’s dig into it: Continue reading NTP Filtering (Delay & Blockage) in the Internet

PGP Key Distribution via DNSSEC: OPENPGPKEY

What is the biggest problem of PGP? The key distribution. This is well-known and not new at all. What is new is the OPENPGPKEY DNS resource record that delivers PGP public keys for mail addresses. If signed and verified with DNSSEC a mail sender can get the correct public key for his recipient. This solves both key distribution problems: 1) the delivery of the public key and 2) the authenticity of the key itself, i.e., that you’re using the correct key to encrypt a mail.

The “DNS-Based Authentication of Named Entities (DANE) Bindings for OpenPGP” is specified in the experimental RFC 7929. Let’s have a look on how you can add your public key into the zone file of your DNS server.

Continue reading PGP Key Distribution via DNSSEC: OPENPGPKEY