Why the BIP-72 Payment Protocol URI Standard is Insecure Against MITM Attacks



Summary:

In a discussion on standardization years ago, BIP72 was rejected as a kludge to incorporate the payment protocol into BIP21. There are many ways to use BIP70 without BIP72, and BIP72 can easily be fixed using a hash parameter. The BIP-70 payment protocol has significant overhead and requires back and forth communication, which is why people prefer to email or print bitcoin addresses on invoices instead. However, the BIP-72 URI's used via the payment protocol are insecure as they do not cryptographically commit to the identity of the merchant. This means that a man-in-the-middle attacker can redirect payment if they can obtain an SSL cert that the wallet accepts. A new BIP is needed to replace BIP72, which is considered very dangerous in its current form.


Updated on: 2023-06-12T19:20:53.456933+00:00