# Cadence: ECDSA secp256k1 Signature Algorithm Change

**URL:** <https://forum.flow.com/t/cadence-ecdsa-secp256k1-signature-algorithm-change/1939>\
**Category:** Breaking Changes\
**Created:** [May 17, 2021, 7:30pm UTC](https://forum.flow.com/t/cadence-ecdsa-secp256k1-signature-algorithm-change/1939 "2021-05-17T19:30:18Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![DrewGarrison](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.flow.com/drewgarrison/32/438_2.png) [@DrewGarrison](https://forum.flow.com/u/DrewGarrison)\
**Post date:** [May 17, 2021, 7:30pm UTC](https://forum.flow.com/t/cadence-ecdsa-secp256k1-signature-algorithm-change/1939/1 "2021-05-17T19:30:18Z")

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We want to let you know that there will be a breaking change to **Cadence** that will impact all development teams. This is a **critical update**.

This change will go into effect: **Wednesday, May 26th**

**Why This Change Happened**

- The naming of the ECDSA secp256k1 signature algorithm was not consistent across different codebases.

**Action Required**

- Replace `SignatureAlgorithm.ECDSA_Secp256k1` with `SignatureAlgorithm.ECDSA_secp256k1`

If you have any questions regarding this breaking change, please ask our team in the **#Cadence** Discord channel for further assistance.