OpenSSH 10.6 Hardens SSH, Enables PQ Signatures

OpenSSH 10.6 prioritizes practical hardening over flashy features—and that is exactly right for foundational infrastructure.

• –Post-quantum signatures extend OpenSSH’s migration beyond key exchange into authentication.
• –Disabling shared compression dictionaries reduces leakage risk but may hurt performance on bandwidth-constrained tunnels.
• –Server-side `WarnWeakCrypto` makes non-post-quantum connections visible during migration.
• –Stricter username validation and `scp -R` deprecation may require updates to automation and deployment scripts.