---
title: "isValidSignature(_:for:)"
framework: cryptokit
role: symbol
role_heading: Instance Method
path: "cryptokit/p256/signing/publickey/isvalidsignature(_:for:)-2rsb5"
---

# isValidSignature(_:for:)

Verifies an elliptic curve digital signature algorithm (ECDSA) signature on a digest over the P-256 elliptic curve.

## Declaration

```swift
func isValidSignature<D>(_ signature: P256.Signing.ECDSASignature, for digest: D) -> Bool where D : Digest
```

## Parameters

- `signature`: The signature to verify.
- `digest`: The signed digest.

## Return Value

Return Value A Boolean value that’s true if the signature is valid for the given digest; otherwise, false.

## See Also

### Verifying a signature

- [isValidSignature(_:for:)](cryptokit/p256/signing/publickey/isvalidsignature(_:for:)-3da2m.md)
- [P256.Signing.ECDSASignature](cryptokit/p256/signing/ecdsasignature.md)