I understand that a long URL is very secure, it’s basically what monzo use to log people into the app, but by receipts the URL isn’t a one time use one so it then has security issues.
I see some nice meals there.
Ham, Egg and chips
Steak and Mash
mmmmm
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I assumed they were signed AWS URLs with an expiry set 
seems it’s not the case
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True, someone might spend a trillion years brute-forcing the URL; that is a concern.
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So long as the eggs aren’t too runny. Then its just disgusting!
With every respect, it is far easier to look at your two publicly accessible social media accounts (twitter, instagram) and build a much more in–depth profile of your life than to try to brute force your shopping receipts.
Anyone can work out your name, age, where you work, where you study, where you live, where and when you travel, where you gym, where you shop, with whom you bank, which other companies provide your mobile phone, life insurance and other services. They can even see you take part in a particular activity which has its own UK Threat Level attached.
From your friends leaking information about you through their interactions with your accounts, anyone can probably build up quite a substantial picture of your entire life to target in any way they choose, not just fraud–related, but concerning your actual personal safety.
You’re already making public vast swathes of your personal life. Aren’t you worried about that?
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Of course, and I’m not saying it isn’t possible to do many things. Plenty of others here have concerns too, so I feel perfectly OK with questioning things my bank does.
What I post online is my choosing and anything that comes from this is my fault and only mine.
Without being on these forums, I would safely assume my banking pictures were secure enough not to cause people to be concerned.
Pulling up my social media accounts isn’t going to exactly cause me to change my mind.
I’m personally not too bothered about the issue, but i think there should definitely be a better implementation,
Nothing can be secure enough to prevent some people being concerned. Basing security assessments on fringe unsubstantiated concerns found on the internet will lead to living in a bunker. 
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I like to think the concerns on this thread are valid, even if it’s only concerning receipts.
The way to convince someone that something is secure is to show it’s secure, not show them that other mediums they use aren’t secure.
As it happens, I am fairly happy with the security explanation above by most people and was basically convinced. The fact others still have concerns though means I still have concerns.
As a regular user and not a coder, it’s believe one or the other without knowledge myself.
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True but they’re computationally infeasible to exploit without privileged access to a user’s device 
My interpretation is that people are trying to show that absolute security is a fiction and that Monzo is as secure as other services that are secure enough
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Talking about social media isn’t doling that though. Saying that other banks do it this way or such things would be. Comparing it to social media avoids the issue.
I’m bowing out here though… seems to be going in circles 
It also shows that the images aren’t encrypted, so any data loss would reveal thousands of customers’ photos.
The images are hosted on AWS (Amazon Web Services), ideally Monzo update to signed URLs, the images then aren’t public and you can then only get through to them via a special URL that expires, could be a single link or have a short expiry. This is then handled by AWS, Monzo just specifies how long the link is valid for.
If this happened then I’d expect the app / developer API to just give you the signed URLs automatically when you ask for an individual transaction and it’s receipts.
If AWS breaks, there’s an awful lot more to worry about than public access of receipts in Monzo…
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When you export your data it includes the links to the receipts , which if they then expire you can’t access them.
Hmm, one time URLs might work but would be annoying, or supply the images with the receipts as separate files/zip?
Maybe supply the base64 data from the image? That’s not particularly friendly though.
Don’t Facebook images have public URLs, even if they’re only set to friends/certain people?
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This is all so far from the end to end encryption to which we should be aspiring… 
Also, two points
- these photos could be much more than receipts
- we shouldn’t take receipts for granted: knowledge of your transactions, your last 4 digits, your location on a certain day, etc could be just the “in” a fraudster needs to scam you
The problem with end to end is the overhead of implementation, do you make users set a passphrase that gets used? That would prevent Monzo from ever being able to see the receipts, but would also make them irrecoverable if you forget it (still guessing some of my BitCoin ones)
The other issue is it could make the experience even slower for some users who are already saying the app is slow if we have to decrypt them on phone, although some messaging apps manage it, so it should be feasible.
I’m all for end to end and many other security features, I’ve previously raised issues in various previous jobs and been told to simply ignore them because of ‘the budget’ or timescales.
I agree that as a bank they shouldn’t have a ton of insecure images though, approaching a million users, that’s a lot of images and enough to put a serious dent in reputation.
Slightly off topic, but still concerning bank/card data, hotels have access to full card details, some might be encrypted, some of them just write then all in a diary that just sits at reception. In some cases it’s probably never locked away.
Some hotels also use third party providers that you have to pass card details to, hopefully over SSL! Some of them probably still send the owner an email containing plain text card details or store all the card details plain text in the database!
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It would be great if an electronic version of a shop receipt could be transmitted when you pay (without having to sign up for e-receipts by email). It is such a waste of paper, especially as most people don’t want/use printed receipts.
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Funny you say that… Flux: The End of Paper Receipts & Loyalty Cards
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