Video -- App assurance: Google insists Gmail access thoroughly vetted.
Google has rolled out its 'confidential mode' for setting a self-destruct date on email to mobile devices.
Confidential mode came with the search company's big redesign of Gmail announced earlier this year and became the default for consumer Gmail users in July, while G Suite business customers still have a few months to make the switch.
The data-protection feature is now available on mobile devices, Google announced via a tweet.
Google promotes the Gmail feature as a way to protect sensitive information by allowing users to set an expiration date for individual messages or revoke access to messages already sent.
The feature also prevents recipients from forwarding, copying, printing or downloading its content and allows users to require recipients to enter a one-time code sent via SMS to view the email.
The authentication feature is intended to protect information in the event of the recipient's email account being hijacked.
While confidential mode could help prevent information leaks, Google notes a few caveats. It won't, for example, prevent recipients from taking screenshots or a snap of the message.
Also, confidentiality could be compromised if the recipient is using a malware-infected computer.
Google is treading more carefully with the rollout of confidential mode for its G Suite users, despite calling confidential mode an "information rights management" control.
The feature is currently off by default in G Suite and users need to ask their admin for permission to access it.
Some people contest Google's use of the word 'confidential', arguing it might mislead people into expecting true confidentiality when in fact it doesn't.
The Electronic Frontier Foundation recently (EFF) accused Google of providing "misleading assurances of privacy and security" with the feature, which could steer users away from finding more secure ways to send private messages.
Its main criticism is that Gmail isn't an end-to-end encrypted service, so Google could read your email.
In response to recent concerns about third-party developers having access to Gmail users' content, Google stressed that no one at Google reads Gmail messages but noted that it can if it needs to, to investigate a bug or abuse.
EFF's other criticism is that expiring emails are only partially erased since they remain in the sender's sent folder after the expiry date and need to be manually deleted from that folder.
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