無料で証明書を発行できるLet’s Encrypt で短期証明書と IP アドレス証明書の一般提供が開始されました．
Short-lived and IP address certificates are now generally available from Let’s Encrypt. These certificates are valid for 160 hours, just over six days. In order to get a short-lived certificate subscribers simply need to select the ‘shortlived’ certificate profile in their ACME client.
興味があるので少し試してみました．