ZKPassport App crashes when generating compressed-evm proof
Hello ZKPassport devs!
I am playing around with the SDK and developing a toy dapp (very sloppy code here). When I scan the QR code and click “Continue” in the ZKPassport App, the app proceeds to generate the proof and starts “compressing”. At the 89% mark, the proof generation/compression appears to crash and the app reverts to the previous screen. Shortly after, I see an error report:
Details:
iPhone 15 Pro
ZKPassport 0.8.5 from AppStore
zkpassport/sdk 0.7.0
Do you know of any possible cause and/or fix? Thanks!
Comments2
Mitchell Douglass
Jul 29, 2025
Hi @Théo Madzou thanks for the reply. I tried clearing the cache. The proof generation still fails at the same point. This time I get a more verbose error:
I am not able to adjust the screen and do not know how to capture the text.
Théo Madzou
Jul 29, 2025
Hey!
Thanks for trying out the SDK. We’re currently trying to find the reason for this issue, actually.
The compression (aka recursion) of the proof sometimes fails.
Some people got it working again by clearing the cache of the app. Which you can do by clicking on the button on the top right here
For more context, when the app reaches the compression step, it has already finished generating what we call the subproofs. The subproofs are ZK proofs, each proving a specific thing about your ID: the first two prove the signatures are valid, the third one that the data signed is indeed the one read from the ID, and the others are the disclosure proofs selectively disclosing whatever information was requested from you.
Compression means these subproofs are sent to the cloud prover, which then recursively verify them so they can be combined into a single proof for easier and cheaper onchain verification, notably. Then sends it back to the app, which sends it to the web app. This is what is failing here, so we need to investigate that