Encryption in Transit

Encryption in transit is the seatbelt of file transfer: invisible when it works, catastrophic to skip, and worth understanding beyond the buzzword. Two technologies do almost all of this work — TLS (behind FTPS and HTTPS) and SSH (behind SFTP and SCP) — and an administrator who understands what they actually protect makes better decisions everywhere else.

This series explains both in plain words: the handshakes, the trust models, the gaps encryption in transit leaves open, how to find the cleartext transfers still hiding on your network, how to set cipher policy without a cryptography degree, and what man-in-the-middle attacks really look like.

Articles in This Series

• How TLS Actually Protects a File Transfer
  The handshake in plain words: certificates establish trust, key exchange builds a shared secret, symmetric encryption carries the data — and what stays visible anyway.
• How SSH Encryption Protects SFTP and SCP
  Host keys, key exchange, and the first-connection trust decision — how SSH's trust model differs from TLS certificates, and what that means day to day.
• What Encryption in Transit Doesn't Protect
  The honest list: files at rest on both ends, compromised endpoints, metadata, and a malicious far side — and how layering closes each gap.
• Finding Cleartext Transfers on Your Network
  Inventory work plus packet-capture spot checks that prove credentials are crossing in the clear — and a remediation order once you find them.
• Cipher Policy Without a Cryptography Degree
  The handful of decisions admins actually make — protocol versions, cipher families, safe defaults — plus how to test an endpoint and when to deviate.
• Man-in-the-Middle Attacks and Trust Failures, Explained
  How interception really works on transfers, why users click through certificate and host-key warnings, and the habits that catch the attack instead.

Explore More Topics

This series is part of the Sysax file transfer topic library, which covers the protocols, security practices, automation techniques, and operational skills behind reliable file transfer. The library pairs well with the practical tools we build: Sysax Multi Server, a secure FTP, FTPS, SFTP, and HTTPS server for Windows, and Sysax FTP Automation, which schedules and scripts secure transfers so the routine ones run themselves.