The party said it enlisted the help of the National Cyber Security Centre (a part of GCHQ – Government Communications Headquarters) to ensure the vote was safe from hackers.
GCHQ had contacted the SNP raising “security considerations” about the online vote, according to the Scottish Mail on Sunday.
The ballot to take over from Sturgeon as SNP leader will run from March 13 to midday on March 27. The vast majority of party members will cast their vote online, though paper ballots are to be available if this option is not.
Online votes are deemed less secure than the paper alternative, with fears that hostile actors could try to influence the outcome.
SNP MP Angus MacNeil said he had written to Peter Murrell, the party’s chief executive, about the issue of vote security.
MacNeil said he was “seeking assurances that the monitoring of the system to choose the next leader is ‘tamper proof’ – that it can’t be interfered with and is seen to be an undisputed result”.
An SNP spokesperson said the party had “taken the appropriate advice and the necessary cyber safeguards are all in place”.
A National Cyber Security Centre spokesperson said: “Defending UK democratic and electoral processes is a priority for the NCSC, and we work closely with all Parliamentary political parties, local authorities and MPs to provide cyber security guidance and support.”
The winner of the vote to take over as SNP leader will be announced on the day which the race closes, March 27.
The ballot will be run on a transferable vote system. This means that members will not vote just once for their preference, but instead rank the candidates from one to three.
If one candidate fails to achieve a majority after the first round of voting, the person with the lowest support will be kicked out of the running. The members who had ranked the losing party top will then have their second preference considered instead.