The SPKI specification defined an authorization certificate format, providing for the delineation of privileges, rights or other such attributes (called authorizations) and binding them to a public key. The original SPKI had identified principals only as public keys but allowed binding authorizations to those keys and delegation of authorization from one key to another. The original SDSI bound local names (of individuals or groups) to public keys (or other names), but carried authorization only in Access Control Lists (ACLs) and did not allow for delegation of subsets of a principal's authorization. The most prominent general deployments of SPKI/SDSI are E-speak, a middleware product from HP that used SPKI/SDSI for access control of web methods, and UPnP Security, that uses an XML dialect of SPKI/SDSI[citation needed] for access control of web methods, delegation of rights among network participants, etc.

The SPKI specification defined an authorization certificate format, providing for the delineation of privileges, rights or other such attributes (called authorizations) and binding them to a public key. The original SPKI had identified principals only as public keys but allowed binding authorizations to those keys and delegation of authorization from one key to another. The original SDSI bound local names (of individuals or groups) to public keys (or other names), but carried authorization only in Access Control Lists (ACLs) and did not allow for delegation of subsets of a principal's authorization. The combined SPKI/SDSI allows the naming of principals, creation of named groups of principals and the delegation of rights or other attributes from one principal to another.

SPKI/SDSI Certificate Documentation [Carl Ellison] SPKI/SDSI Certificates SPKI, SDSI and the other certificate mechanisms from 1996 onward started out to address apparent overcomplication in the X.509 world. There are five certificate syntax forms referenced from this page:  SPKI/SDSI, X.509, PGP, X9.59 (AADS), PolicyMaker and KeyNote. The SPKI/SDSI certificate format is the product of the SPKI Working Group of the IETF. The theory behind SPKI certificates has been summarized in a journal paper:  Ellison, ``The nature of a usable PKI'', Computer Networks 31 (1999) pp. Carl Ellison, ``Establishing Identity Without Certification Authorities'', 6th USENIX Security Symposium , 1996. The IETF XML Digital Signature Working Group, core draft (8) includes the data structure (in KeyInfo) for holding SPKI-encoded public keys and/or certificates backing up an XML signature.

The SPKI specification defined an authorization certificate format, providing for the delineation of privileges, rights or other such attributes (called authorizations) and binding them to a public key. The original SPKI had identified principals only as public keys but allowed binding authorizations to those keys and delegation of authorization from one key to another. The original SDSI bound local names (of individuals or groups) to public keys (or other names), but carried authorization only in Access Control Lists (ACLs) and did not allow for delegation of subsets of a principal's authorization. The most prominent general deployments of SPKI/SDSI are E-speak, a middleware product from HP that used SPKI/SDSI for access control of web methods, and UPnP Security, that uses an XML dialect of SPKI/SDSI[citation needed] for access control of web methods, delegation of rights among network participants, etc.

The SPKI specification defined an authorization certificate format, providing for the delineation of privileges, rights or other such attributes (called authorizations) and binding them to a public key. The original SPKI had identified principals only as public keys but allowed binding authorizations to those keys and delegation of authorization from one key to another. The original SDSI bound local names (of individuals or groups) to public keys (or other names), but carried authorization only in Access Control Lists (ACLs) and did not allow for delegation of subsets of a principal's authorization. The combined SPKI/SDSI allows the naming of principals, creation of named groups of principals and the delegation of rights or other attributes from one principal to another.

SPKI/SDSI Certificate Documentation [Carl Ellison] SPKI/SDSI Certificates SPKI, SDSI and the other certificate mechanisms from 1996 onward started out to address apparent overcomplication in the X.509 world. There are five certificate syntax forms referenced from this page:  SPKI/SDSI, X.509, PGP, X9.59 (AADS), PolicyMaker and KeyNote. The SPKI/SDSI certificate format is the product of the SPKI Working Group of the IETF. The theory behind SPKI certificates has been summarized in a journal paper:  Ellison, ``The nature of a usable PKI'', Computer Networks 31 (1999) pp. Carl Ellison, ``Establishing Identity Without Certification Authorities'', 6th USENIX Security Symposium , 1996. The IETF XML Digital Signature Working Group, core draft (8) includes the data structure (in KeyInfo) for holding SPKI-encoded public keys and/or certificates backing up an XML signature.