After HeartBleed, POODLE and FREAK encryption flaws, a new encryption attack has been emerged.  This is called Logjam allows attackers to read and modify the sensitive data passing through encrypted connections, potentially affecting hundreds of thousands of HTTPS-protected sites, mail servers, and other widely used Internet services. Logjam can be exploited on a subset of servers that support the widely used cryptographic algorithm called the "Diffie-Hellman key exchange," which allows protocols like HTTPS, SSH, SMTPS, IPsec to negotiate a secret key and create a secure connection.