Install ca-cacert by entering the following commands in the terminal:
sudo apt update sudo apt install ca-cacert
CAcert.org root certificates
This package provides CAcert.org (sub-)root certificates in PEM format. Root certificates allow SSL-based applications to check for the authenticity of certificates issued by the CAcert authority. . CAcert.org is a community-driven Certificate Authority that issues certificates to the public for free. . CAcert's goal is to promote awareness and education on computer security through the use of encryption, specifically by providing cryptographic certificates. These certificates can be used to digitally sign and encrypt email, authenticate and authorize users connecting to websites and secure data transmission over the internet. Any application that supports the Secure Socket Layer Protocol (SSL or TLS) can make use of certificates signed by CAcert, as can any application that uses X.509 certificates, e.g. for encryption or code signing and document signatures. . Please note that CAcert may not yet comply with RFC 3647 or similar standards.