Fundamentally, you can’t call digital communication secure unless it fulfills four principles: encryption, authentication, integrity, and non-repudiation. So, when businesses send messages, it should be with end-to-end encryption. Meanwhile, encryption algorithms and network sniffing tools can help authenticate users to protect against attackers intercepting the communication. Digital certificates and biometric identification are also commonly relied on to prove authenticity. The integrity of a communication refers to it not being tampered with or modified, and whoever receives it is confident it hasn’t been. Digital signatures, message authentication codes, and data hashing handle this. Finally, non-repudiation means that the sender of a message/transaction can’t deny they’ve sent it after the recipient has received the message. So, it refers to evidence that the communication exists. Again, this uses digital signatures, message authentication codes, and timestamps. More generally, a few comprehensive tools that drive communication security are worth noting. Secure Sockets Layer (SSL) and TLS (Transport Layer Security) encrypt communications between clients (browsers) and servers (websites/ applications). Of the two, TLS is the newer and better regarded. Furthermore, Pretty Good Privacy (PGP) tackles the encryption/decryption of emails over the Internet, while Virtual Private Networks (VPNs) are fast becoming another major player. VPNs are commonly used because they connect remote users to a private network, avoiding shared public networks. A VPN boasts in-built security features for authentication and data privacy, and, increasingly, many businesses are turning to them for these reasons.