; and (iv) will fully implement the appropriate and effective call authentication framework under clause (i), not later than 18 months after the date of enactment of this Act, subject to subparagraph (B); and (B) may extend the deadline for implementation of the call authentication framework under paragraph (1) or subparagraph (A) of this paragraph, as applicable, for an additional 12 months, or such further time as the Federal Communications Commission determines to be necessary, for a provider that demonstrates substantial hardship in purchasing or upgrading equipment to support call authentication. (b) Safe harbor and other regulations (1) In general The Federal Communications Commission shall promulgate rules— (A) affirming authority for a provider of voice service to block a voice call pursuant to the authentication framework under paragraph (1) or paragraph (2) of subsection (a), as applicable; (B) establishing a safe harbor for a provider of voice service from liability for unintended or inadvertent blocking of calls or for the unintended or inadvertent misidentification of the level of trust for individual calls pursuant to the authentication framework under paragraph (1) or paragraph (2) of subsection (a), as applicable; and (C) establishing a process to permit a calling party adversely affected by the authentication framework under paragraph (1) or paragraph (2) of subsection (a), as applicable, to verify the authenticity of the calling party's calls. (2) Considerations In establishing the safe harbor under paragraph (1), the Federal Communications Commission shall consider limiting the liability of providers based on the extent to which they— (A) block or identify calls based on the authentication framework under paragraph (1) or paragraph (2) of subsection (a), as applicable; (B) implemented procedures based on the framework