18 (b) before notification to the Commissioner or the Zimbabwe Revenue Authority by the registered user that the security of the digital signature allocated to him or her has been compromised; the Commissioner or the Zimbabwe Revenue Authority shall be entitled to assume that such data has been communicated by, or with the authority of, the registered user of that digital signature. (3) Where in any proceedings or prosecution under this Act or in any dispute to which the Zimbabwe Revenue Authority is a party, the question arises whether an digital signature affixed to any electronic communication to the Commissioner or the Zimbabwe Revenue Authority was used in such communication with or without the consent and authority of the registered user, it shall be presumed, in the absence of proof to the contrary, that such signature was so used with the consent and authority of the registered user. 80K Alternatives to electronic communication in certain cases (1) Whenever a computer system established in terms of section 80D or any other computer system of a registered user is inoperative, the registered user and the Commissioner shall communicate with each other in writing in the manner prescribed in this Act. (2) The Commissioner may at any time require from any registered user the submission of any original document required to be produced under any of the provisions of this Act. 80L Unlawful uses of computer systems (1) A person who, not being the registered user of a digital signature to whom it is allocated, uses such a signature in any electronic communication to the Commissioner or the Zimbabwe Revenue Authority without the authority of such registered user, commits an offence and is liable to a fine not exceeding level twelve or to imprisonment for a period not exceeding ten years or to both such fine and such imprisonment. (2) A person who— (a) makes a false electronic record or falsifies an electronic record; or (b) dishonestly or fraudulently— (i) makes, affixes any digital signature to, transmits or executes an electronic record or communication; or (ii) causes any other person to make, affix any digital signature to, execute, transmit or execute an electronic record or communication; commits an offence and is liable to a fine not exceeding level twelve or to imprisonment for a period not exceeding ten years or to both such fine and such imprisonment.”. 20 Amendment of section 90 of Cap. 23:06 With effect from the 1st January, 2007, section 90 (“Regulations”) (1) of the Income Tax Act [Chapter 23:06] is amended by the repeal of paragraph (d) and the substitution⎯