N.Y. Comp. Codes R. & Regs. tit. 7, § 6.4 – Proof of identity.

(a) When a request is made in person, or when records are made available in person following a request made by mail, the department may require appropriate identification, such as a driver's license, an identifier assigned to the data subject by the department, a photograph or similar information that confirms that the record sought pertains to the data subject.
(b) When a request is made by mail, the department may require verification of a signature or inclusion of an identifier generally known only by a data subject, or similar appropriate identification.
(c) Proof of identity shall not be required regarding a request for a record accessible to the public pursuant to article 6 of the Public Officers Law.