Certificate Packages

org.bouncycastle.cert	Basic support package for handling and creating X.509 certificates, CRLs, and attribute certificates.
org.bouncycastle.cert.bc
org.bouncycastle.cert.cmp	Basic support package for handling and creating CMP (RFC 4210) certificate management messages.
org.bouncycastle.cert.crmf	Basic support package for handling and creating CRMF (RFC 4211) certificate request messages.
org.bouncycastle.cert.crmf.bc
org.bouncycastle.cert.crmf.jcajce	JCA extensions to the CRMF online certificate request package.
org.bouncycastle.cert.dane
org.bouncycastle.cert.dane.fetcher
org.bouncycastle.cert.jcajce	JCA extensions to the certificate building and processing package.
org.bouncycastle.cert.ocsp	Basic support package for handling and creating OCSP (RFC 2560) online certificate status requests.
org.bouncycastle.cert.ocsp.jcajce	JCA extensions to the OCSP online certificate status package.
org.bouncycastle.cert.path
org.bouncycastle.cert.path.validations
org.bouncycastle.cert.selector	Specialised Selector classes for certificates, CRLs, and attribute certificates.
org.bouncycastle.cert.selector.jcajce
org.bouncycastle.mozilla	Support class for mozilla signed public key and challenge.
org.bouncycastle.mozilla.jcajce

Cryptographic Operators

org.bouncycastle.operator	Basic operator definitions for doing encryption, signing, and digest operations.
org.bouncycastle.operator.bc	Basic operator implementations for doing encryption, signing, and digest operations using the BC lightweight API.
org.bouncycastle.operator.jcajce	Basic operator implementations for doing encryption, signing, and digest operations using the JCA and the JCE.

CMS Packages

org.bouncycastle.cms	A package for processing RFC 3852 Cryptographic Message Syntax (CMS) objects - also referred to as PKCS#7 (formerly RFC 2630, 3369).
org.bouncycastle.cms.bc	CMS operator implementations for doing message encryption, signing, digesting, and MACing operations using the BC lightweight API.
org.bouncycastle.cms.jcajce	CMS operator implementations for doing message encryption, signing, digesting, and MACing operations using the JCA and the JCE.

DVCS Packages

org.bouncycastle.dvcs

Classes for dealing "Internet X.509 Public Key Infrastructure Data Validation and Certification Server Protocols" - RFC 3029.

Extended Access Control Packages

org.bouncycastle.eac	Base classes Extended Access Control (EAC) Certificates as described in "Technical Guideline, Advanced Security Mechanisms for Machine Readable Travel Documents, Extended Access Control (EAC), Version 1.0.1, BSI 2006".
org.bouncycastle.eac.jcajce
org.bouncycastle.eac.operator
org.bouncycastle.eac.operator.jcajce

PKCS Packages

org.bouncycastle.pkcs	Basic support package for handling and creating PKCS#10 certification requests, PKCS#8 encrypted keys and PKCS#12 keys stores.
org.bouncycastle.pkcs.bc	BC lightweight API extensions and operators for the PKCS#10 certification request package.
org.bouncycastle.pkcs.jcajce	JCA extensions and operators for the PKCS#10 certification request package.

OpenSSL and PEM Support Packages

org.bouncycastle.openssl	Classes for dealing with OpenSSL PEM files.
org.bouncycastle.openssl.bc
org.bouncycastle.openssl.jcajce

TSP Packages

org.bouncycastle.tsp	Classes for dealing Time Stamp Protocol (TSP) - RFC 3161.
org.bouncycastle.tsp.cms	Classes for dealing Syntax for Binding Documents with Time-Stamps - RFC 5544.
org.bouncycastle.tsp.ers

Other Packages

org.bouncycastle.pkix
org.bouncycastle.pkix.jcajce
org.bouncycastle.pkix.util
org.bouncycastle.pkix.util.filter