JCE Utility and Extension Packages

org.bouncycastle.jce	Utility classes for use with the JCE.
org.bouncycastle.jce.examples	Example classes for use with the JCE.
org.bouncycastle.jce.exception
org.bouncycastle.jce.interfaces	Interfaces for supporting Elliptic Curve Keys, El Gamal, and PKCS12 attributes.
org.bouncycastle.jce.netscape
org.bouncycastle.jce.spec	Parameter specifications for supporting El Gamal, and Elliptic Curve.

OCSP and OpenSSL PEM Support Packages

org.bouncycastle.ocsp	Classes for dealing Online Certificate Status Protocol (OCSP) - RFC 2560.
org.bouncycastle.ocsp.test	Test class for OCSP messages.
org.bouncycastle.openssl	Classes for dealing with OpenSSL PEM files.
org.bouncycastle.openssl.test	Test class for OpenSSL PEMReader.

ASN.1 Support Packages

org.bouncycastle.asn1	A library for parsing and writing ASN.1 objects.
org.bouncycastle.asn1.cmp	Support classes useful for encoding and supporting PKIX-CMP as described RFC 2510.
org.bouncycastle.asn1.cms	Support classes useful for encoding and supporting Cryptographic Message Syntax as described in PKCS#7 and RFC 3369 (formerly RFC 2630).
org.bouncycastle.asn1.cryptopro	Support classes for CRYPTO-PRO related objects - such as GOST identifiers.
org.bouncycastle.asn1.esf	Support classes useful for encoding and supporting [ESF] RFC3126 Electronic Signature Formats for long term electronic signatures.
org.bouncycastle.asn1.ess	Support classes useful for encoding and supporting Enhanced Security Services for S/MIME as described RFC 2634.
org.bouncycastle.asn1.gnu
org.bouncycastle.asn1.iana
org.bouncycastle.asn1.icao	ICAO ASN.1 classes for electronic passport.
org.bouncycastle.asn1.isismtt
org.bouncycastle.asn1.isismtt.ocsp
org.bouncycastle.asn1.isismtt.x509
org.bouncycastle.asn1.kisa
org.bouncycastle.asn1.microsoft
org.bouncycastle.asn1.misc	Miscellaneous object identifiers and objects.
org.bouncycastle.asn1.mozilla	Support classes useful for encoding objects used by mozilla.
org.bouncycastle.asn1.nist	Support classes for NIST related objects.
org.bouncycastle.asn1.ntt
org.bouncycastle.asn1.ocsp	Support classes useful for encoding and supporting OCSP objects.
org.bouncycastle.asn1.oiw	Objects and OID for the support of ISO OIW.
org.bouncycastle.asn1.pkcs	Support classes useful for encoding and supporting the various RSA PKCS documents.
org.bouncycastle.asn1.sec	Classes for support of the SEC standard for Elliptic Curve.
org.bouncycastle.asn1.smime	Support classes useful for encoding and supporting S/MIME.
org.bouncycastle.asn1.teletrust	Support classes for TeleTrust related objects.
org.bouncycastle.asn1.tsp	Support classes useful for encoding and supporting Time Stamp Protocol as described RFC 3161.
org.bouncycastle.asn1.util	An ASN.1 dump utility.
org.bouncycastle.asn1.x500
org.bouncycastle.asn1.x509	Support classes useful for encoding and processing X.509 certificates.
org.bouncycastle.asn1.x509.qualified	Support classes useful for encoding and processing messages based around RFC3739
org.bouncycastle.asn1.x509.sigi
org.bouncycastle.asn1.x9	Support classes useful for encoding and supporting X9.62 elliptic curve.

Lightweight Crypto Packages

org.bouncycastle.crypto	Base classes for the lightweight API.
org.bouncycastle.crypto.agreement	Basic key agreement classes.
org.bouncycastle.crypto.agreement.kdf
org.bouncycastle.crypto.digests	Message digest classes.
org.bouncycastle.crypto.encodings	Block encodings for asymmetric ciphers.
org.bouncycastle.crypto.engines	Basic cipher classes.
org.bouncycastle.crypto.examples	Simple examples of light weight API usage.
org.bouncycastle.crypto.generators	Generators for keys, key pairs and password based encryption algorithms.
org.bouncycastle.crypto.io	Classes for doing "enhanced" I/O with Digests and MACs.
org.bouncycastle.crypto.macs	Classes for creating MACs and HMACs.
org.bouncycastle.crypto.modes	Modes for symmetric ciphers.
org.bouncycastle.crypto.paddings	Paddings for symmetric ciphers.
org.bouncycastle.crypto.params	Classes for parameter objects for ciphers and generators.
org.bouncycastle.crypto.prng	Lightweight psuedo-random number generators.
org.bouncycastle.crypto.signers	Basic signers.
org.bouncycastle.crypto.tls	A lightweight TLS API.
org.bouncycastle.crypto.util	Some general utility/conversion classes.

Utility Packages

org.bouncycastle.util
org.bouncycastle.util.encoders	Classes for producing and reading Base64 and Hex strings.
org.bouncycastle.util.test	Light weight test API.

JCE Provider and Test Classes

org.bouncycastle.jce.provider
org.bouncycastle.jce.provider.symmetric
org.bouncycastle.jce.provider.test
org.bouncycastle.jce.provider.test.nist
org.bouncycastle.jce.provider.test.rsa3

Other Packages

org.bouncycastle.mozilla	Support class for mozilla signed public key and challenge.
org.bouncycastle.x509	Classes for supporting the generation of X.509 certificates and X.509 attribute certificates.
org.bouncycastle.x509.examples	Examples for X.509 attribute certificates.
org.bouncycastle.x509.extension	Helper classes for dealing with common X.509 extensions.
org.bouncycastle.x509.util