are secured by a perfected security interest in or other perfected lien on the cover pool when the estate is created. The estate shall not be liable on any obligation of the issuer that is not secured by a perfected security interest in or other perfected lien on the cover pool when the estate is created. No conservator, receiver, liquidating agent, or trustee in bankruptcy for the issuer may charge or assess the estate for any claim of the conservator, receiver, liquidating agent, or trustee in bankruptcy or the conservatorship, receivership, liquidating agency, or estate in bankruptcy and may not obtain or perfect a security interest in or other lien on the cover pool to secure such a claim. (3) Retention of claims Any holder of a covered bond or related obligation for which an estate has become liable under paragraph (2) shall retain a claim against the issuer for any deficiency with respect to the covered bond or related obligation. If the issuer enters conservatorship, receivership, liquidation, or bankruptcy, any contingent claim for such a deficiency shall be allowed as a provable claim in the conservatorship, receivership, liquidating agency, or bankruptcy case. The contingent claim shall be estimated by the conservator, receiver, liquidating agent, or bankruptcy court for purposes of allowing the claim as a provable claim if awaiting the fixing of the contingent claim would unduly delay the resolution of the conservatorship, receivership, liquidating agency, or bankruptcy case. (4) Residual interest (A) Issuance of residual interest Upon the creation of an estate under paragraph (1), a residual interest in the estate shall be immediately and automatically issued by operation of law to the issuer. (B) Nature of residual interest The residual interest under subparagraph (A) shall— (i) be an exempted security as described in section 344