Abstract: SNAP (Standar Nasional OPEN API Pembayaran) was submitted by
several sub-working groups formed jointly by ASPI and the Bank of Indonesia for
encouraging digital transformation in the banking industry. In the document
Pedoman Tata Kelola (Bank of Indonesia, n.d.), there is the use cryptographic
algorithms that are used as validation for third parties to use the Open API. The
algorithms used in the document are HMAC and RSA. However, there are other
algorithms that can be used as a form of validation, such as ECC and ZK-SNARK.
ECC uses an elliptic curve as a standard cryptography calculation which can use
shorter keys than RSA. On the other hand, ZK-SNARK uses a pairing-based
elliptic curve which makes verification calculations simpler. The method used as
authentication in SNAP is the third party will send the signature in the API header
along with the sent API payload. The signature describes the body payload, the
endpoint URL that was called by the third party, and the time when the API call
was made, so the signature will change all the time. In this research, the
performance of the four cryptographic algorithms is compared based on SNAP
method. The performance we compare is overall speed of process when creating
the signature and verifying it. The result is that HMAC is the most efficient
algorithm, but for financial data, it is better to use ECC which uses asymmetric
keys and is faster than RSA contained in the SNAP document, especially when 256
bits security level that ECC could be 10 times faster then RSA.
Keywords: cryptographic, ECC, HMAC, performance, RSA, SNAP, ZK-SNARK,