Snapchat suffered a nasty surprise back in October when a third-party app that archived images and videos posted to the ephemeral messaging app suffered a security breach that allowed hackers to get their hands on masses of private Snapchat content.

It was a big embarrassment for the startup, even though its own servers were not hit in the attack. Since then, it's been working on ways to make it more difficult for third-party apps to access its content, which include asking Apple and Google to remove offending software from their app stores.

This week, however, Snapchat said it's now found a way of reliably blocking all third-party apps from accessing the messaging software's data. In doing so, the LA-based startup hopes to reduce the chances of further difficult incidents down the road, while improving users' security.

The move appears to be part of an ongoing effort to portray itself as a more serious and responsible enterprise as it continues to attract marketers and investors to its fast-expanding product.

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Speaking to Backchannel recently, Snapchat executives admitted it should've been more assertive in cracking down on third-party apps that let users archive content, an action that was in direct conflict with the app's main feature and consequently violated its terms of service.

"We never wanted third-party apps on our platform," Snapchat's Tim Sehn told Backchannel. "We have created a product where it is more critically important than ever before that we control the end user experience. We've made commitments to our users."

Transparency report

News that Snapchat has shored up its security coincided with the publication of details of its first ever transparency report, due out in July. Similar to reports put out by tech giants like Apple, Microsoft, and Google, Snapchat promises to detail government requests received for users' account information, government demands to remove users' content, and requests to remove content that violates copyright law.

In a preview of July's report, Snapchat revealed it received 375 information requests from the U.S. government in connection with 666 accounts from November 1, 2014 through February 28 of this year. Outside of the U.S., it received just 28 requests for 35 accounts.

This week's developments come at a time of rapid expansion for Snapchat. Besides growing its user base, which most commentators put at between 100 million and 200 million, the company has also increased its team from 35 to 200 in the space of a year, and built out its app with a slew of new features.

The startup continues to attract huge amounts of investment, too, including some $486 million in late 2014, and a reported $200 million just recently, from Chinese Internet giant Alibaba.