Restoration of Freedom of Information Act of 2005 - Amends the Homeland Security Act of 2002 to prohibit a record pertaining to the vulnerability of and threats to critical infrastructure that is furnished voluntarily to the Department of Homeland Security from being made available to the public under the Freedom of Information Act if: (1) the provider would not customarily make the record available to the public; and (2) the record is designated and certified by the provider as confidential and not customarily made available to the public. Prohibits other Federal agencies in receipt of such a record furnished to the Department from making the record publicly available. Allows a provider to withdraw the confidential designation of a record at any time.