IT lexicon Security Let's Encrypt

Let's Encrypt

Security På svenska → Updated: 2026-07-28
More info
Creator
Internet Security Research Group
Released
Type
Certificate authority
Website

The free, automated certificate authority that single-handedly made HTTPS the default on the web.

Before 2015 a certificate cost money and required manual work every year, so most small sites ran unencrypted. Let's Encrypt issues free DV certificates entirely automatically over the ACME protocol — certbot solves a challenge, collects the certificate and renews it for you.

Certificates last only 90 days, deliberately: it forces automation and limits the damage from a leaked key. Run by ISRG. The share of encrypted web traffic went from roughly 40% to over 90% in the years after launch.

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