Never heard of covered bonds? Reuters does a nice job of explaining what they are:
Covered bonds are securities issued by banks and backed by mortgage or public-sector loans.
Unlike the loans behind existing mortgage- and asset-backed securities, covered bond loans remain on the balance sheet of the bank issuing the bond, making the bonds obligations of the bank. The issuer keeps control of the assets and can change the make-up of the loan pool as well as alter the terms of the loans.
Covered bonds offer long-term funding to borrowers for long-term and relatively low-credit risk investments, such as acquisition or construction of residential, commercial or agricultural property, public investment and ships.
These things have been around since 1770 in Europe. Forbes also points out that in addition to helping the mortgage market covered bonds could help with infrastructure projects. This could be a big deal if done right.