Microsoft SEAL vs Themis: Side-by-Side Comparison (2026)

Themis

Development teams building applications that handle sensitive authentication data or need encryption primitives without vendor lock-in should start with Themis. It's open-source with 1,954 GitHub stars and provides cryptographic services across authentication, storage, and messaging in a single library, letting you avoid piecing together multiple dependencies. The tradeoff: Themis is a low-level building block, not a managed data masking platform; it requires engineering effort to integrate and won't give you the policy engine or compliance reporting that off-the-shelf data masking tools provide.