Exhibit 23

Consent of KPMG LLP, Independent Registered Public Accounting Firm of Ambac Assurance Corporation

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The Board of Directors

Ambac Assurance Corporation:

We consent to the incorporation by reference in the registration statement (No. 333-133985) of Structured Asset Securities Corporation (the “Registrant”) in the Prospectus and in the Prospectus Supplement of the Registrant relating to Lehman XS Trust Mortgage Pass-Through Certificates, Series 2007-7N (the “Prospectus Supplement”), of our report dated February 28, 2007 on the consolidated financial statements of Ambac Assurance Corporation and subsidiaries as of December 31, 2006 and 2005, and for each of the years in the three-year period ended December 31, 2006, which report appears in the Annual Report on Form 10-K of Ambac Financial Group, Inc., which was filed with the Securities and Exchange Commission on March 1, 2007, and to the reference to our firm under the heading “Experts” in the Prospectus Supplement. Our report refers to changes, in 2006, in Ambac Assurance Corporation’s methods of accounting for variable interest entities and stock-based compensation.

/s/ KPMG LLP

New York, New York

May 29, 2007

Lehman XS Trust Series 2007-7N 8-K