Power of Attorney for Gregory Mumford, CFO of Cipher Mining Inc.

Gregory Mumford, Chief Financial Officer of Cipher Mining Inc., has executed a Power of Attorney document. This document appoints individuals listed on Schedule A, including Tyler Page and William Iwaschuk, as his attorneys-in-fact. These attorneys are authorized to prepare, execute, and submit various SEC forms (Forms 3, 4, and 5) on behalf of Mr. Mumford. They are also empowered to take any necessary actions related to these filings, including obtaining and regenerating codes and passwords for electronic filings. The Power of Attorney remains in effect until Mr. Mumford is no longer required to file these forms, unless revoked earlier in writing. The document was executed on October 15, 2025.