The way I read it no they don't. From Commonwealth Electoral Act 1918
https://www.legislation.gov.au/Details/C2019C00103/Download
“240 Marking of votes in House of Representatives election (1) In a House of Representatives election a person shall mark his or her vote on the ballot paper by: (a) writing the number 1 in the square opposite the name of the candidate for whom the person votes as his or her first preference; and (b) writing the numbers 2, 3, 4 (and so on, as the case requires) in the squares opposite the names of all the remaining candidates so as to indicate the order of the person’s preference for them. (2) The numbers referred to in paragraph (1)(b) are to be consecutive numbers, without the repetition of any number
268 Informal ballot papers (1) A ballot paper shall (except as otherwise provided by section 239, and by the regulations relating to voting by post) be informal if
© in a House of Representatives election, it has no vote indicated on it, or it does not indicate the voter’s first preference for 1 candidate and an order of preference for all the remaining candidates:”
The way I interpret this, literally, is that provided the numbers increase they do not have to start at one.
The section 239 referred to in section 268 refers to the Senate.
Section 240 used the word “ shell” not must. But even if it did use the word, must, section 268 Trump's it.
From Commonwealth Electoral Act 1918
https://www.legislation.gov.au/Details/C2019C00103/Download
Any other organisation or person can on the payment of a fee obtain a copy of an Electoral Role.
Section 90B (4) Item 3
A candidate or registered political party can at no charge obtain a copy of an Electoral Role.
Section 90B (1)
Australia Post plans blockchain-based e-voting system
https://delimiter.com.au/2016/08/23/australia-post-plans-blockchain-based-e-voting-system/
Australia
American
http://theconversation.com/how-hard-is-it-to-rig-an-election-67374