diff --git a/crates/core/Cargo.toml b/crates/core/Cargo.toml
index 9c7ac367e8..c72f372c54 100644
--- a/crates/core/Cargo.toml
+++ b/crates/core/Cargo.toml
@@ -10,9 +10,10 @@ edition = "2021"
 
 [features]
 default = []
-fixtures = ["dep:hex"]
+fixtures = ["dep:hex", "dep:tlsn-data-fixtures"]
 
 [dependencies]
+tlsn-data-fixtures = { workspace = true, optional = true }
 tlsn-tls-core = { workspace = true, features = ["serde"] }
 tlsn-utils = { workspace = true }
 
@@ -29,6 +30,7 @@ k256 = { workspace = true }
 opaque-debug = { workspace = true }
 p256 = { workspace = true, features = ["serde"] }
 rand = { workspace = true }
+rand_core = { workspace = true }
 rs_merkle = { workspace = true, features = ["serde"] }
 rstest = { workspace = true, optional = true }
 serde = { workspace = true }
@@ -41,7 +43,6 @@ webpki-roots = { workspace = true }
 [dev-dependencies]
 rstest = { workspace = true }
 hex = { workspace = true }
-rand_core = { workspace = true }
 rand_chacha = { workspace = true }
 bincode = { workspace = true }
 tlsn-data-fixtures = { workspace = true }
diff --git a/crates/core/src/attestation/builder.rs b/crates/core/src/attestation/builder.rs
index 2c3b43f13f..a2dc674ead 100644
--- a/crates/core/src/attestation/builder.rs
+++ b/crates/core/src/attestation/builder.rs
@@ -237,3 +237,234 @@ impl std::fmt::Display for AttestationBuilderError {
         Ok(())
     }
 }
+
+#[cfg(test)]
+mod test {
+    use rstest::{fixture, rstest};
+    use tlsn_data_fixtures::http::{request::GET_WITH_HEADER, response::OK_JSON};
+
+    use crate::{
+        connection::{HandshakeData, HandshakeDataV1_2},
+        fixtures::{encoder_seed, encoding_provider, ConnectionFixture},
+        hash::Blake3,
+        request::RequestConfig,
+        transcript::{encoding::EncodingTree, Transcript, TranscriptCommitConfigBuilder},
+    };
+
+    use super::*;
+
+    fn request_and_connection() -> (Request, ConnectionFixture) {
+        let provider = CryptoProvider::default();
+
+        let transcript = Transcript::new(GET_WITH_HEADER, OK_JSON);
+        let (sent_len, recv_len) = transcript.len();
+        // Plaintext encodings which the Prover obtained from GC evaluation
+        let encodings_provider = encoding_provider(GET_WITH_HEADER, OK_JSON);
+
+        // At the end of the TLS connection the Prover holds the:
+        let ConnectionFixture {
+            server_name,
+            server_cert_data,
+            ..
+        } = ConnectionFixture::tlsnotary(transcript.length());
+
+        // Prover specifies the ranges it wants to commit to.
+        let mut transcript_commitment_builder = TranscriptCommitConfigBuilder::new(&transcript);
+        transcript_commitment_builder
+            .commit_sent(&(0..sent_len))
+            .unwrap()
+            .commit_recv(&(0..recv_len))
+            .unwrap();
+
+        let transcripts_commitment_config = transcript_commitment_builder.build().unwrap();
+
+        // Prover constructs encoding tree.
+        let encoding_tree = EncodingTree::new(
+            &Blake3::default(),
+            transcripts_commitment_config.iter_encoding(),
+            &encodings_provider,
+            &transcript.length(),
+        )
+        .unwrap();
+
+        let request_config = RequestConfig::default();
+        let mut request_builder = Request::builder(&request_config);
+
+        request_builder
+            .server_name(server_name.clone())
+            .server_cert_data(server_cert_data)
+            .transcript(transcript.clone())
+            .encoding_tree(encoding_tree);
+        let (request, _) = request_builder.build(&provider).unwrap();
+
+        (request, ConnectionFixture::tlsnotary(transcript.length()))
+    }
+
+    #[fixture]
+    #[once]
+    fn default_attestation_config() -> AttestationConfig {
+        AttestationConfig::builder()
+            .supported_signature_algs([SignatureAlgId::SECP256K1])
+            .build()
+            .unwrap()
+    }
+
+    #[fixture]
+    #[once]
+    fn crypto_provider() -> CryptoProvider {
+        let mut provider = CryptoProvider::default();
+        provider.signer.set_secp256k1(&[42u8; 32]).unwrap();
+        provider
+    }
+
+    #[rstest]
+    fn test_attestation_builder_accept_unsupported_signer() {
+        let (request, _) = request_and_connection();
+        let attestation_config = AttestationConfig::builder()
+            .supported_signature_algs([SignatureAlgId::SECP256R1])
+            .build()
+            .unwrap();
+
+        let err = Attestation::builder(&attestation_config)
+            .accept_request(request)
+            .err()
+            .unwrap();
+        assert!(err.is_request());
+    }
+
+    #[rstest]
+    fn test_attestation_builder_accept_unsupported_hasher() {
+        let (request, _) = request_and_connection();
+
+        let attestation_config = AttestationConfig::builder()
+            .supported_signature_algs([SignatureAlgId::SECP256K1])
+            .supported_hash_algs([HashAlgId::KECCAK256])
+            .build()
+            .unwrap();
+
+        let err = Attestation::builder(&attestation_config)
+            .accept_request(request)
+            .err()
+            .unwrap();
+        assert!(err.is_request());
+    }
+
+    #[rstest]
+    fn test_attestation_builder_accept_unsupported_encoding_commitment() {
+        let (request, _) = request_and_connection();
+
+        let attestation_config = AttestationConfig::builder()
+            .supported_signature_algs([SignatureAlgId::SECP256K1])
+            .supported_fields([
+                FieldKind::ConnectionInfo,
+                FieldKind::ServerEphemKey,
+                FieldKind::ServerIdentityCommitment,
+            ])
+            .build()
+            .unwrap();
+
+        let err = Attestation::builder(&attestation_config)
+            .accept_request(request)
+            .err()
+            .unwrap();
+        assert!(err.is_request());
+    }
+
+    #[rstest]
+    fn test_attestation_builder_sign_missing_signer(
+        default_attestation_config: &AttestationConfig,
+    ) {
+        let (request, _) = request_and_connection();
+
+        let attestation_builder = Attestation::builder(default_attestation_config)
+            .accept_request(request.clone())
+            .unwrap();
+
+        let mut provider = CryptoProvider::default();
+        provider.signer.set_secp256r1(&[42u8; 32]).unwrap();
+
+        let err = attestation_builder.build(&provider).err().unwrap();
+        assert!(matches!(err.kind, ErrorKind::Config));
+    }
+
+    #[rstest]
+    fn test_attestation_builder_sign_missing_encoding_seed(
+        default_attestation_config: &AttestationConfig,
+        crypto_provider: &CryptoProvider,
+    ) {
+        let (request, connection) = request_and_connection();
+
+        let mut attestation_builder = Attestation::builder(default_attestation_config)
+            .accept_request(request.clone())
+            .unwrap();
+
+        let ConnectionFixture {
+            connection_info,
+            server_cert_data,
+            ..
+        } = connection;
+
+        let HandshakeData::V1_2(HandshakeDataV1_2 {
+            server_ephemeral_key,
+            ..
+        }) = server_cert_data.handshake.clone();
+
+        attestation_builder
+            .connection_info(connection_info.clone())
+            .server_ephemeral_key(server_ephemeral_key);
+
+        let err = attestation_builder.build(crypto_provider).err().unwrap();
+        assert!(matches!(err.kind, ErrorKind::Field));
+    }
+
+    #[rstest]
+    fn test_attestation_builder_sign_missing_server_ephemeral_key(
+        default_attestation_config: &AttestationConfig,
+        crypto_provider: &CryptoProvider,
+    ) {
+        let (request, connection) = request_and_connection();
+
+        let mut attestation_builder = Attestation::builder(default_attestation_config)
+            .accept_request(request.clone())
+            .unwrap();
+
+        let ConnectionFixture {
+            connection_info, ..
+        } = connection;
+
+        attestation_builder
+            .connection_info(connection_info.clone())
+            .encoding_seed(encoder_seed().to_vec());
+
+        let err = attestation_builder.build(crypto_provider).err().unwrap();
+        assert!(matches!(err.kind, ErrorKind::Field));
+    }
+
+    #[rstest]
+    fn test_attestation_builder_sign_missing_connection_info(
+        default_attestation_config: &AttestationConfig,
+        crypto_provider: &CryptoProvider,
+    ) {
+        let (request, connection) = request_and_connection();
+
+        let mut attestation_builder = Attestation::builder(default_attestation_config)
+            .accept_request(request.clone())
+            .unwrap();
+
+        let ConnectionFixture {
+            server_cert_data, ..
+        } = connection;
+
+        let HandshakeData::V1_2(HandshakeDataV1_2 {
+            server_ephemeral_key,
+            ..
+        }) = server_cert_data.handshake.clone();
+
+        attestation_builder
+            .server_ephemeral_key(server_ephemeral_key)
+            .encoding_seed(encoder_seed().to_vec());
+
+        let err = attestation_builder.build(crypto_provider).err().unwrap();
+        assert!(matches!(err.kind, ErrorKind::Field));
+    }
+}
diff --git a/crates/core/src/connection.rs b/crates/core/src/connection.rs
index b142b3c98c..30a30324b2 100644
--- a/crates/core/src/connection.rs
+++ b/crates/core/src/connection.rs
@@ -376,3 +376,291 @@ pub enum CertificateVerificationError {
     #[error("invalid server ephemeral key")]
     InvalidServerEphemeralKey,
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::{fixtures::ConnectionFixture, transcript::Transcript};
+
+    use hex::FromHex;
+    use rstest::*;
+    use tlsn_data_fixtures::http::{request::GET_WITH_HEADER, response::OK_JSON};
+
+    #[fixture]
+    #[once]
+    fn crypto_provider() -> CryptoProvider {
+        CryptoProvider::default()
+    }
+
+    fn tlsnotary() -> ConnectionFixture {
+        ConnectionFixture::tlsnotary(Transcript::new(GET_WITH_HEADER, OK_JSON).length())
+    }
+
+    fn appliedzkp() -> ConnectionFixture {
+        ConnectionFixture::appliedzkp(Transcript::new(GET_WITH_HEADER, OK_JSON).length())
+    }
+
+    /// Expect chain verification to succeed.
+    #[rstest]
+    #[case::tlsnotary(tlsnotary())]
+    #[case::appliedzkp(appliedzkp())]
+    fn test_verify_cert_chain_sucess_ca_implicit(
+        crypto_provider: &CryptoProvider,
+        #[case] mut data: ConnectionFixture,
+    ) {
+        // Remove the CA cert
+        data.server_cert_data.certs.pop();
+
+        assert!(data
+            .server_cert_data
+            .verify_with_provider(
+                crypto_provider,
+                data.connection_info.time,
+                data.server_ephemeral_key(),
+                &ServerName::from(data.server_name.as_ref()),
+            )
+            .is_ok());
+    }
+
+    /// Expect chain verification to succeed even when a trusted CA is provided
+    /// among the intermediate certs. webpki handles such cases properly.
+    #[rstest]
+    #[case::tlsnotary(tlsnotary())]
+    #[case::appliedzkp(appliedzkp())]
+    fn test_verify_cert_chain_success_ca_explicit(
+        crypto_provider: &CryptoProvider,
+        #[case] data: ConnectionFixture,
+    ) {
+        assert!(data
+            .server_cert_data
+            .verify_with_provider(
+                crypto_provider,
+                data.connection_info.time,
+                data.server_ephemeral_key(),
+                &ServerName::from(data.server_name.as_ref()),
+            )
+            .is_ok());
+    }
+
+    /// Expect to fail since the end entity cert was not valid at the time.
+    #[rstest]
+    #[case::tlsnotary(tlsnotary())]
+    #[case::appliedzkp(appliedzkp())]
+    fn test_verify_cert_chain_fail_bad_time(
+        crypto_provider: &CryptoProvider,
+        #[case] data: ConnectionFixture,
+    ) {
+        // unix time when the cert chain was NOT valid
+        let bad_time: u64 = 1571465711;
+
+        let err = data.server_cert_data.verify_with_provider(
+            crypto_provider,
+            bad_time,
+            data.server_ephemeral_key(),
+            &ServerName::from(data.server_name.as_ref()),
+        );
+
+        assert!(matches!(
+            err.unwrap_err(),
+            CertificateVerificationError::InvalidCert
+        ));
+    }
+
+    /// Expect to fail when no intermediate cert provided.
+    #[rstest]
+    #[case::tlsnotary(tlsnotary())]
+    #[case::appliedzkp(appliedzkp())]
+    fn test_verify_cert_chain_fail_no_interm_cert(
+        crypto_provider: &CryptoProvider,
+        #[case] mut data: ConnectionFixture,
+    ) {
+        // Remove the CA cert
+        data.server_cert_data.certs.pop();
+        // Remove the intermediate cert
+        data.server_cert_data.certs.pop();
+
+        let err = data.server_cert_data.verify_with_provider(
+            crypto_provider,
+            data.connection_info.time,
+            data.server_ephemeral_key(),
+            &ServerName::from(data.server_name.as_ref()),
+        );
+
+        assert!(matches!(
+            err.unwrap_err(),
+            CertificateVerificationError::InvalidCert
+        ));
+    }
+
+    /// Expect to fail when no intermediate cert provided even if a trusted CA
+    /// cert is provided.
+    #[rstest]
+    #[case::tlsnotary(tlsnotary())]
+    #[case::appliedzkp(appliedzkp())]
+    fn test_verify_cert_chain_fail_no_interm_cert_with_ca_cert(
+        crypto_provider: &CryptoProvider,
+        #[case] mut data: ConnectionFixture,
+    ) {
+        // Remove the intermediate cert
+        data.server_cert_data.certs.remove(1);
+
+        let err = data.server_cert_data.verify_with_provider(
+            crypto_provider,
+            data.connection_info.time,
+            data.server_ephemeral_key(),
+            &ServerName::from(data.server_name.as_ref()),
+        );
+
+        assert!(matches!(
+            err.unwrap_err(),
+            CertificateVerificationError::InvalidCert
+        ));
+    }
+
+    /// Expect to fail because end-entity cert is wrong.
+    #[rstest]
+    #[case::tlsnotary(tlsnotary())]
+    #[case::appliedzkp(appliedzkp())]
+    fn test_verify_cert_chain_fail_bad_ee_cert(
+        crypto_provider: &CryptoProvider,
+        #[case] mut data: ConnectionFixture,
+    ) {
+        let ee: &[u8] = include_bytes!("./fixtures/data/unknown/ee.der");
+
+        // Change the end entity cert
+        data.server_cert_data.certs[0] = Certificate(ee.to_vec());
+
+        let err = data.server_cert_data.verify_with_provider(
+            crypto_provider,
+            data.connection_info.time,
+            data.server_ephemeral_key(),
+            &ServerName::from(data.server_name.as_ref()),
+        );
+
+        assert!(matches!(
+            err.unwrap_err(),
+            CertificateVerificationError::InvalidCert
+        ));
+    }
+
+    /// Expect sig verification to fail because client_random is wrong.
+    #[rstest]
+    #[case::tlsnotary(tlsnotary())]
+    #[case::appliedzkp(appliedzkp())]
+    fn test_verify_sig_ke_params_fail_bad_client_random(
+        crypto_provider: &CryptoProvider,
+        #[case] mut data: ConnectionFixture,
+    ) {
+        let HandshakeData::V1_2(HandshakeDataV1_2 { client_random, .. }) =
+            &mut data.server_cert_data.handshake;
+        client_random[31] = client_random[31].wrapping_add(1);
+
+        let err = data.server_cert_data.verify_with_provider(
+            crypto_provider,
+            data.connection_info.time,
+            data.server_ephemeral_key(),
+            &ServerName::from(data.server_name.as_ref()),
+        );
+
+        assert!(matches!(
+            err.unwrap_err(),
+            CertificateVerificationError::InvalidServerSignature
+        ));
+    }
+
+    /// Expect sig verification to fail because the sig is wrong.
+    #[rstest]
+    #[case::tlsnotary(tlsnotary())]
+    #[case::appliedzkp(appliedzkp())]
+    fn test_verify_sig_ke_params_fail_bad_sig(
+        crypto_provider: &CryptoProvider,
+        #[case] mut data: ConnectionFixture,
+    ) {
+        data.server_cert_data.sig.sig[31] = data.server_cert_data.sig.sig[31].wrapping_add(1);
+
+        let err = data.server_cert_data.verify_with_provider(
+            crypto_provider,
+            data.connection_info.time,
+            data.server_ephemeral_key(),
+            &ServerName::from(data.server_name.as_ref()),
+        );
+
+        assert!(matches!(
+            err.unwrap_err(),
+            CertificateVerificationError::InvalidServerSignature
+        ));
+    }
+
+    /// Expect to fail because the dns name is not in the cert.
+    #[rstest]
+    #[case::tlsnotary(tlsnotary())]
+    #[case::appliedzkp(appliedzkp())]
+    fn test_check_dns_name_present_in_cert_fail_bad_host(
+        crypto_provider: &CryptoProvider,
+        #[case] data: ConnectionFixture,
+    ) {
+        let bad_name = ServerName::from("badhost.com");
+
+        let err = data.server_cert_data.verify_with_provider(
+            crypto_provider,
+            data.connection_info.time,
+            data.server_ephemeral_key(),
+            &bad_name,
+        );
+
+        assert!(matches!(
+            err.unwrap_err(),
+            CertificateVerificationError::InvalidCert
+        ));
+    }
+
+    /// Expect to fail because the ephemeral key provided is wrong.
+    #[rstest]
+    #[case::tlsnotary(tlsnotary())]
+    #[case::appliedzkp(appliedzkp())]
+    fn test_invalid_ephemeral_key(
+        crypto_provider: &CryptoProvider,
+        #[case] data: ConnectionFixture,
+    ) {
+        let wrong_ephemeral_key = ServerEphemKey {
+            typ: KeyType::SECP256R1,
+            key: Vec::<u8>::from_hex(include_bytes!("./fixtures/data/unknown/pubkey")).unwrap(),
+        };
+
+        let err = data.server_cert_data.verify_with_provider(
+            crypto_provider,
+            data.connection_info.time,
+            &wrong_ephemeral_key,
+            &ServerName::from(data.server_name.as_ref()),
+        );
+
+        assert!(matches!(
+            err.unwrap_err(),
+            CertificateVerificationError::InvalidServerEphemeralKey
+        ));
+    }
+
+    /// Expect to fail when no cert provided.
+    #[rstest]
+    #[case::tlsnotary(tlsnotary())]
+    #[case::appliedzkp(appliedzkp())]
+    fn test_verify_cert_chain_fail_no_cert(
+        crypto_provider: &CryptoProvider,
+        #[case] mut data: ConnectionFixture,
+    ) {
+        // Empty certs
+        data.server_cert_data.certs = Vec::new();
+
+        let err = data.server_cert_data.verify_with_provider(
+            crypto_provider,
+            data.connection_info.time,
+            data.server_ephemeral_key(),
+            &ServerName::from(data.server_name.as_ref()),
+        );
+
+        assert!(matches!(
+            err.unwrap_err(),
+            CertificateVerificationError::MissingCerts
+        ));
+    }
+}
diff --git a/crates/core/src/fixtures.rs b/crates/core/src/fixtures.rs
index ba580a80eb..44ab905fd6 100644
--- a/crates/core/src/fixtures.rs
+++ b/crates/core/src/fixtures.rs
@@ -83,7 +83,7 @@ impl ConnectionFixture {
                     Certificate(include_bytes!("fixtures/data/appliedzkp.org/ca.der").to_vec()),
                 ],
                 sig: ServerSignature {
-                    scheme: SignatureScheme::RSA_PKCS1_SHA256,
+                    scheme: SignatureScheme::ECDSA_NISTP256_SHA256,
                     sig: Vec::<u8>::from_hex(include_bytes!(
                         "fixtures/data/appliedzkp.org/signature"
                     ))
@@ -109,6 +109,15 @@ impl ConnectionFixture {
             },
         }
     }
+
+    /// Returns the server_ephemeral_key fixture.
+    pub fn server_ephemeral_key(&self) -> &ServerEphemKey {
+        let HandshakeData::V1_2(HandshakeDataV1_2 {
+            server_ephemeral_key,
+            ..
+        }) = &self.server_cert_data.handshake;
+        server_ephemeral_key
+    }
 }
 
 /// Returns an encoding provider fixture.
diff --git a/crates/core/src/fixtures/data/unknown/pubkey b/crates/core/src/fixtures/data/unknown/pubkey
new file mode 100644
index 0000000000..e9166c19fe
--- /dev/null
+++ b/crates/core/src/fixtures/data/unknown/pubkey
@@ -0,0 +1 @@
+14e1f634ecfee5bd4f987f8c571146cb2acb432e400b2fabcbd8ed77f6ef08bd5496cd51d449ce131efd74a24d07b01c38ec794d22d3d43b2b05b907e72797534e
\ No newline at end of file
diff --git a/crates/core/src/index.rs b/crates/core/src/index.rs
index 3187cb8549..6e974f5ef0 100644
--- a/crates/core/src/index.rs
+++ b/crates/core/src/index.rs
@@ -104,3 +104,74 @@ impl From<Vec<PlaintextHashSecret>> for Index<PlaintextHashSecret> {
         })
     }
 }
+
+#[cfg(test)]
+mod test {
+    use utils::range::RangeSet;
+
+    use super::*;
+
+    #[derive(PartialEq, Debug, Clone)]
+    struct Stub {
+        field_index: FieldId,
+        index: Idx,
+    }
+
+    impl From<Vec<Stub>> for Index<Stub> {
+        fn from(items: Vec<Stub>) -> Self {
+            Self::new(items, |item: &Stub| (&item.field_index, &item.index))
+        }
+    }
+
+    fn stubs() -> Vec<Stub> {
+        vec![
+            Stub {
+                field_index: FieldId(1),
+                index: Idx::new(RangeSet::from([0..1, 18..21])),
+            },
+            Stub {
+                field_index: FieldId(2),
+                index: Idx::new(RangeSet::from([1..5, 8..11])),
+            },
+        ]
+    }
+
+    #[test]
+    fn test_successful_retrieval() {
+        let stub_a_index = Idx::new(RangeSet::from([0..4, 7..10]));
+        let stub_b_field_index = FieldId(8);
+
+        let stubs = vec![
+            Stub {
+                field_index: FieldId(1),
+                index: stub_a_index.clone(),
+            },
+            Stub {
+                field_index: stub_b_field_index,
+                index: Idx::new(RangeSet::from([1..5, 8..11])),
+            },
+        ];
+        let stubs_index: Index<Stub> = stubs.clone().into();
+
+        assert_eq!(
+            stubs_index.get_by_field_id(&stub_b_field_index),
+            Some(&stubs[1])
+        );
+        assert_eq!(
+            stubs_index.get_by_transcript_idx(&stub_a_index),
+            Some(&stubs[0])
+        );
+    }
+
+    #[test]
+    fn test_failed_retrieval() {
+        let stubs = stubs();
+        let stubs_index: Index<Stub> = stubs.clone().into();
+
+        let wrong_index = Idx::new(RangeSet::from([0..3, 4..5]));
+        let wrong_field_index = FieldId(200);
+
+        assert_eq!(stubs_index.get_by_field_id(&wrong_field_index), None);
+        assert_eq!(stubs_index.get_by_transcript_idx(&wrong_index), None);
+    }
+}
diff --git a/crates/core/src/request.rs b/crates/core/src/request.rs
index c165b3b162..32818ac6d7 100644
--- a/crates/core/src/request.rs
+++ b/crates/core/src/request.rs
@@ -87,3 +87,171 @@ impl Request {
 #[derive(Debug, thiserror::Error)]
 #[error("inconsistent attestation: {0}")]
 pub struct InconsistentAttestation(String);
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    use crate::{
+        attestation::{Attestation, AttestationConfig},
+        connection::{HandshakeData, HandshakeDataV1_2, ServerCertOpening, TranscriptLength},
+        fixtures::{encoder_seed, encoding_provider, ConnectionFixture},
+        hash::{Blake3, Hash, HashAlgId},
+        signing::SignatureAlgId,
+        transcript::{encoding::EncodingTree, Transcript, TranscriptCommitConfigBuilder},
+        CryptoProvider,
+    };
+
+    use tlsn_data_fixtures::http::{request::GET_WITH_HEADER, response::OK_JSON};
+
+    fn attestation(payload: (Request, ConnectionFixture)) -> Attestation {
+        let (request, connection) = payload;
+
+        let ConnectionFixture {
+            connection_info,
+            server_cert_data,
+            ..
+        } = connection;
+
+        let HandshakeData::V1_2(HandshakeDataV1_2 {
+            server_ephemeral_key,
+            ..
+        }) = server_cert_data.handshake.clone();
+
+        let mut provider = CryptoProvider::default();
+        provider.signer.set_secp256k1(&[42u8; 32]).unwrap();
+
+        let attestation_config = AttestationConfig::builder()
+            .supported_signature_algs([SignatureAlgId::SECP256K1])
+            .build()
+            .unwrap();
+
+        let mut attestation_builder = Attestation::builder(&attestation_config)
+            .accept_request(request.clone())
+            .unwrap();
+
+        attestation_builder
+            .connection_info(connection_info.clone())
+            .server_ephemeral_key(server_ephemeral_key)
+            .encoding_seed(encoder_seed().to_vec());
+
+        attestation_builder.build(&provider).unwrap()
+    }
+
+    fn request_and_connection() -> (Request, ConnectionFixture) {
+        let provider = CryptoProvider::default();
+
+        let transcript = Transcript::new(GET_WITH_HEADER, OK_JSON);
+        let (sent_len, recv_len) = transcript.len();
+        // Plaintext encodings which the Prover obtained from GC evaluation
+        let encodings_provider = encoding_provider(GET_WITH_HEADER, OK_JSON);
+
+        // At the end of the TLS connection the Prover holds the:
+        let ConnectionFixture {
+            server_name,
+            server_cert_data,
+            ..
+        } = ConnectionFixture::tlsnotary(transcript.length());
+
+        // Prover specifies the ranges it wants to commit to.
+        let mut transcript_commitment_builder = TranscriptCommitConfigBuilder::new(&transcript);
+        transcript_commitment_builder
+            .commit_sent(&(0..sent_len))
+            .unwrap()
+            .commit_recv(&(0..recv_len))
+            .unwrap();
+
+        let transcripts_commitment_config = transcript_commitment_builder.build().unwrap();
+
+        // Prover constructs encoding tree.
+        let encoding_tree = EncodingTree::new(
+            &Blake3::default(),
+            transcripts_commitment_config.iter_encoding(),
+            &encodings_provider,
+            &transcript.length(),
+        )
+        .unwrap();
+
+        let request_config = RequestConfig::default();
+        let mut request_builder = Request::builder(&request_config);
+
+        request_builder
+            .server_name(server_name.clone())
+            .server_cert_data(server_cert_data)
+            .transcript(transcript.clone())
+            .encoding_tree(encoding_tree);
+        let (request, _) = request_builder.build(&provider).unwrap();
+
+        (request, ConnectionFixture::tlsnotary(transcript.length()))
+    }
+
+    #[test]
+    fn test_success() {
+        let (request, connection) = request_and_connection();
+
+        let attestation = attestation((request.clone(), connection));
+
+        assert!(request.validate(&attestation).is_ok())
+    }
+
+    #[test]
+    fn test_wrong_signature_alg() {
+        let (mut request, connection) = request_and_connection();
+
+        let attestation = attestation((request.clone(), connection));
+
+        request.signature_alg = SignatureAlgId::SECP256R1;
+
+        let res = request.validate(&attestation);
+        assert!(res.is_err());
+    }
+
+    #[test]
+    fn test_wrong_hash_alg() {
+        let (mut request, connection) = request_and_connection();
+
+        let attestation = attestation((request.clone(), connection));
+
+        request.hash_alg = HashAlgId::SHA256;
+
+        let res = request.validate(&attestation);
+        assert!(res.is_err())
+    }
+
+    #[test]
+    fn test_wrong_server_commitment() {
+        let (mut request, connection) = request_and_connection();
+
+        let attestation = attestation((request.clone(), connection));
+
+        let ConnectionFixture {
+            server_cert_data, ..
+        } = ConnectionFixture::appliedzkp(TranscriptLength {
+            sent: 100,
+            received: 100,
+        });
+        let opening = ServerCertOpening::new(server_cert_data);
+
+        let crypto_provider = CryptoProvider::default();
+        request.server_cert_commitment =
+            opening.commit(crypto_provider.hash.get(&HashAlgId::BLAKE3).unwrap());
+
+        let res = request.validate(&attestation);
+        assert!(res.is_err())
+    }
+
+    #[test]
+    fn test_wrong_encoding_commitment_root() {
+        let (mut request, connection) = request_and_connection();
+
+        let attestation = attestation((request.clone(), connection));
+
+        request.encoding_commitment_root = Some(TypedHash {
+            alg: HashAlgId::BLAKE3,
+            value: Hash::default(),
+        });
+
+        let res = request.validate(&attestation);
+        assert!(res.is_err())
+    }
+}
diff --git a/crates/core/src/signing.rs b/crates/core/src/signing.rs
index 13edbace37..eb2c902231 100644
--- a/crates/core/src/signing.rs
+++ b/crates/core/src/signing.rs
@@ -372,3 +372,78 @@ mod secp256r1 {
 }
 
 pub use secp256r1::{Secp256r1Signer, Secp256r1Verifier};
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use rand_core::OsRng;
+    use rstest::{fixture, rstest};
+
+    #[fixture]
+    #[once]
+    fn secp256k1_signer() -> Secp256k1Signer {
+        let signing_key = k256::ecdsa::SigningKey::random(&mut OsRng);
+        Secp256k1Signer::new(&signing_key.to_bytes()).unwrap()
+    }
+
+    #[fixture]
+    #[once]
+    fn secp256r1_signer() -> Secp256r1Signer {
+        let signing_key = p256::ecdsa::SigningKey::random(&mut OsRng);
+        Secp256r1Signer::new(&signing_key.to_bytes()).unwrap()
+    }
+
+    #[rstest]
+    fn test_secp256k1_success(secp256k1_signer: &Secp256k1Signer) {
+        assert_eq!(secp256k1_signer.alg_id(), SignatureAlgId::SECP256K1);
+
+        let msg = "test payload";
+        let signature = secp256k1_signer.sign(msg.as_bytes()).unwrap();
+        let verifying_key = secp256k1_signer.verifying_key();
+
+        let verifier = Secp256k1Verifier {};
+        assert_eq!(verifier.alg_id(), SignatureAlgId::SECP256K1);
+        let result = verifier.verify(&verifying_key, msg.as_bytes(), &signature.data);
+        assert!(result.is_ok());
+    }
+
+    #[rstest]
+    fn test_secp256r1_success(secp256r1_signer: &Secp256r1Signer) {
+        assert_eq!(secp256r1_signer.alg_id(), SignatureAlgId::SECP256R1);
+
+        let msg = "test payload";
+        let signature = secp256r1_signer.sign(msg.as_bytes()).unwrap();
+        let verifying_key = secp256r1_signer.verifying_key();
+
+        let verifier = Secp256r1Verifier {};
+        assert_eq!(verifier.alg_id(), SignatureAlgId::SECP256R1);
+        let result = verifier.verify(&verifying_key, msg.as_bytes(), &signature.data);
+        assert!(result.is_ok());
+    }
+
+    #[rstest]
+    #[case::wrong_signer(&secp256r1_signer(), false, false)]
+    #[case::corrupted_signature(&secp256k1_signer(), true, false)]
+    #[case::wrong_signature(&secp256k1_signer(), false, true)]
+    fn test_failure(
+        #[case] signer: &dyn Signer,
+        #[case] corrupted_signature: bool,
+        #[case] wrong_signature: bool,
+    ) {
+        let msg = "test payload";
+        let mut signature = signer.sign(msg.as_bytes()).unwrap();
+        let verifying_key = signer.verifying_key();
+
+        if corrupted_signature {
+            signature.data.push(0);
+        }
+
+        if wrong_signature {
+            signature = signer.sign("different payload".as_bytes()).unwrap();
+        }
+
+        let verifier = Secp256k1Verifier {};
+        let result = verifier.verify(&verifying_key, msg.as_bytes(), &signature.data);
+        assert!(result.is_err());
+    }
+}