# Secure File Transfer (SFTP, FTPS, AS2) One-sentence definition: Protocols and practices to securely move files with confidentiality, integrity, and nonrepudiation options. ## Key Facts - SFTP (SSH), FTPS (TLS), AS2 (HTTPS + signatures/encryption + MDNs). - Use mutual auth, allowlists, and chroot/sandbox directories. - Automate hashing/signing; retain receipts/MDNs. - Monitor transfers; rotate credentials/keys; limit egress paths. - Replace ad-hoc email/USB sharing with managed gateways. - **Verify:** check official (ISC)² CBK and current exam outline. ## Exam Relevance - Choose the protocol providing legal-grade receipts (AS2/MDN). **Mnemonic:** “Move it, **prove** it.” ## Mini Scenario Q: Partner needs proof file was received unaltered—solution? A: AS2 with signed MDNs. ## Revision Checklist - Contrast SFTP vs FTPS vs AS2. - Name 2 hardening steps. - State one monitoring control. ## Related [[Email Security for Data Protection (SPF, DKIM, DMARC, DLP)]] · [[Data Sharing and External Collaboration Controls]] · [[Hashing and Checksums for Data Integrity]] · [[Backups for Data Protection (Domain 2 view)]] · [[Removable Media and Portable Storage Policy]] · [[Domain 2 - Index]]