What is Encryption in Transit?
Encryption in Transit is the practice of encrypting data while it moves across a network so that only the intended sender and receiver can read it. It protects data from interception, eavesdropping, and tampering during transmission, most commonly using the TLS protocol.
What it is
Encryption in Transit means data is encrypted before it leaves one system and decrypted only after it arrives at the destination. The most common mechanism is TLS (Transport Layer Security), which secures HTTP, email, database connections, API calls, and file transfers. Older protocols like SSL are deprecated and considered insecure. Mutual TLS (mTLS) extends the model by requiring both sides of a connection to present certificates, not just the server.
The concept sits alongside two related ideas: encryption at rest (protecting stored data) and encryption in use, also called confidential computing (protecting data while it is being processed).
Why it matters
Without encryption in transit, any system on the network path can read or modify data in plain text. This includes ISPs, cloud providers, internal network segments, and anyone who has compromised a router or switch. Regulatory frameworks including PCI DSS, HIPAA, and GDPR explicitly require encryption of data in transit. A missing or misconfigured TLS certificate can expose sensitive data and trigger compliance failures.
Certificate expiry is a common operational failure. An expired certificate breaks encrypted connections and can take services offline. Certificate Lifecycle Management (CLM) tools exist specifically to track and renew certificates before they expire.
How tools address it
No single product category is called "encryption in transit software." Instead, multiple tool types enforce or support it:
- TLS termination and inspection is handled by load balancers, API gateways, and web application firewalls.
- Certificate Lifecycle Management tools automate certificate issuance, renewal, and revocation across an environment.
- Managed File Transfer platforms enforce encrypted channels (SFTP, FTPS, AS2) for bulk file movement between organizations.