12. 特許情報 English
（準備中）
下記の米国特許 related to data validation and certification services,
listed in chronological order,
are known by the authors to exist at this time.
これは、網羅的なリストではない。他の特許が、
may exist or be issued at any time.
Implementers of the DVCS protocol and applications using the protocol
は、自身で調査し、
whether or not any encumberences exist on their implementation
を判断する必要がある（SHOULD）。# 4,309,569 Method of Providing Digital Signatures (issued)
January 5, 1982 (inventor) Ralph C. Merkle (assignee) The Board of Trustees of the Leland Stanford Junior University# 5,001,752 Public/Key Date-Time Notary Facility (issued)
March 19, 1991 (inventor) Addison M. Fischer# 5,022,080 Electronic Notary (issued)
June 4, 1991 (inventors) Robert T. Durst, Kevin D. Hunter# 5,136,643 Public/Key Date-Time Notary Facility (issued)
August 4, 1992 (inventor) Addison M. Fischer (Note: This is a continuation of patent # 5,001,752.)# 5,136,646 Digital Document Time-Stamping with Catenate Certificate (issued)
August 4, 1992 (inventors) Stuart A. Haber, Wakefield S. Stornetta Jr. (assignee) Bell Communications Research, Inc.,# 5,136,647 Method for Secure Time-Stamping of Digital Documents (issued)
August 4, 1992 (inventors) Stuart A. Haber, Wakefield S. Stornetta Jr. (assignee) Bell Communications Research, Inc.,# 5,373,561 Method of Extending the Validity of a Cryptographic Certificate (issued)
December 13, 1994 (inventors) Stuart A. Haber, Wakefield S. Stornetta Jr. (assignee) Bell Communications Research, Inc.,# 5,422,95 Personal Date/Time Notary Device (issued)
June 6, 1995 (inventor) Addison M. Fischer# 5,781,629 Digital Document Authentication System (issued)
July 14, 1998 (inventor) Stuart A. Haber, Wakefield S. Stornetta Jr. (assignee) Surety Technologies, Inc.,