Bouncy Castle Cryptographic APIs

Bouncy Castle is a collection of open-source cryptographic APIs for Java and C Sharp dot NET, providing comprehensive implementations of encryption, decryption, digital signatures, certificate management, and secure messaging protocols for over 20 years. The project offers FIPS-certified versions that meet the rigorous requirements of United States Federal Information Processing Standards, with LTS releases ensuring long-term stability for production deployments. The latest Java release is version 1.84 and the LTS release is 2.73.11, both including quantum-ready cryptographic support to address the emerging threat of post-quantum computing attacks on classical public-key algorithms. The Java API provides implementations for symmetric ciphers including AES, ChaCha20, and Serpent, asymmetric algorithms including RSA, DSA, ECDSA, and EdDSA, key agreement protocols including Diffie-Hellman and ECDH, message digests including SHA-2 and SHA-3 families, MAC algorithms including HMAC and Poly1305, and X.509 certificate generation and parsing. The C Sharp dot NET API mirrors the Java functionality with platform-specific optimizations. Both libraries support CMS and S/MIME for secure email, OpenPGP for encrypted file exchange, TLS and DTLS for secure transport, OCSP for certificate status checking, and TSP for timestamping. The Keyfactor Community provides professional support, training, and consulting through Keyfactor Inc. Related open-source projects include EJBCA for enterprise certificate authority operations, SignServer for automated digital signing workflows, and integration with OpenSSL. The #KEYMASTER technical series covers topics including SCEP relevance in post-quantum environments, PKI hierarchy scaling lessons from the field, and certificate lifecycle management best practices. Monthly downloads number in the millions, with active community discussion on GitHub Discussions for both the Java and C Sharp repositories.