IL SB3643

Defines "cryptocurrency" as a virtual currency using cryptography to secure transactions recorded on a distributed ledger like blockchain.

Defines "cryptocurrency mining" as the process where computers validate blockchain transactions and receive mining rewards for computational efforts.

Modifies "qualifying Illinois data center" definition to include data centers engaged in cryptocurrency mining operations over a 60-month period beginning no earlier than 60 months before the bill's effective date.

Extends tax exemption eligibility to cryptocurrency mining data centers that meet the same $250 million capital investment and 20 full-time job creation requirements as traditional data centers.

Maintains existing exemptions from retailers' occupation tax, use tax, and income tax credits for qualifying data centers, with certificates of exemption not to exceed 20 calendar years and no new certificates issued after July 1, 2029.