diff --git a/identity/aidl/default/IdentityCredential.cpp b/identity/aidl/default/IdentityCredential.cpp
index 341fae6..aaae1f6 100644
--- a/identity/aidl/default/IdentityCredential.cpp
+++ b/identity/aidl/default/IdentityCredential.cpp
@@ -102,7 +102,7 @@
 }
 
 ndk::ScopedAStatus IdentityCredential::deleteCredential(
-        vector<int8_t>* outProofOfDeletionSignature) {
+        vector<uint8_t>* outProofOfDeletionSignature) {
     cppbor::Array array = {"ProofOfDeletion", docType_, testCredential_};
     vector<uint8_t> proofOfDeletion = array.encode();
 
@@ -115,11 +115,11 @@
                 IIdentityCredentialStore::STATUS_FAILED, "Error signing data"));
     }
 
-    *outProofOfDeletionSignature = byteStringToSigned(signature.value());
+    *outProofOfDeletionSignature = signature.value();
     return ndk::ScopedAStatus::ok();
 }
 
-ndk::ScopedAStatus IdentityCredential::createEphemeralKeyPair(vector<int8_t>* outKeyPair) {
+ndk::ScopedAStatus IdentityCredential::createEphemeralKeyPair(vector<uint8_t>* outKeyPair) {
     optional<vector<uint8_t>> kp = support::createEcKeyPair();
     if (!kp) {
         return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
@@ -135,13 +135,13 @@
     }
     ephemeralPublicKey_ = publicKey.value();
 
-    *outKeyPair = byteStringToSigned(kp.value());
+    *outKeyPair = kp.value();
     return ndk::ScopedAStatus::ok();
 }
 
 ndk::ScopedAStatus IdentityCredential::setReaderEphemeralPublicKey(
-        const vector<int8_t>& publicKey) {
-    readerPublicKey_ = byteStringToUnsigned(publicKey);
+        const vector<uint8_t>& publicKey) {
+    readerPublicKey_ = publicKey;
     return ndk::ScopedAStatus::ok();
 }
 
@@ -169,8 +169,8 @@
 // ahead of time.
 bool checkReaderAuthentication(const SecureAccessControlProfile& profile,
                                const vector<uint8_t>& readerCertificateChain) {
-    optional<vector<uint8_t>> acpPubKey = support::certificateChainGetTopMostKey(
-            byteStringToUnsigned(profile.readerCertificate.encodedCertificate));
+    optional<vector<uint8_t>> acpPubKey =
+            support::certificateChainGetTopMostKey(profile.readerCertificate.encodedCertificate);
     if (!acpPubKey) {
         LOG(ERROR) << "Error extracting public key from readerCertificate in profile";
         return false;
@@ -255,13 +255,9 @@
 
 ndk::ScopedAStatus IdentityCredential::startRetrieval(
         const vector<SecureAccessControlProfile>& accessControlProfiles,
-        const HardwareAuthToken& authToken, const vector<int8_t>& itemsRequestS,
-        const vector<int8_t>& signingKeyBlobS, const vector<int8_t>& sessionTranscriptS,
-        const vector<int8_t>& readerSignatureS, const vector<int32_t>& requestCounts) {
-    auto sessionTranscript = byteStringToUnsigned(sessionTranscriptS);
-    auto itemsRequest = byteStringToUnsigned(itemsRequestS);
-    auto readerSignature = byteStringToUnsigned(readerSignatureS);
-
+        const HardwareAuthToken& authToken, const vector<uint8_t>& itemsRequest,
+        const vector<uint8_t>& signingKeyBlob, const vector<uint8_t>& sessionTranscript,
+        const vector<uint8_t>& readerSignature, const vector<int32_t>& requestCounts) {
     if (sessionTranscript.size() > 0) {
         auto [item, _, message] = cppbor::parse(sessionTranscript);
         if (item == nullptr) {
@@ -498,7 +494,7 @@
     currentNameSpace_ = "";
 
     itemsRequest_ = itemsRequest;
-    signingKeyBlob_ = byteStringToUnsigned(signingKeyBlobS);
+    signingKeyBlob_ = signingKeyBlob;
 
     numStartRetrievalCalls_ += 1;
     return ndk::ScopedAStatus::ok();
@@ -605,10 +601,8 @@
     return ndk::ScopedAStatus::ok();
 }
 
-ndk::ScopedAStatus IdentityCredential::retrieveEntryValue(const vector<int8_t>& encryptedContentS,
-                                                          vector<int8_t>* outContent) {
-    auto encryptedContent = byteStringToUnsigned(encryptedContentS);
-
+ndk::ScopedAStatus IdentityCredential::retrieveEntryValue(const vector<uint8_t>& encryptedContent,
+                                                          vector<uint8_t>* outContent) {
     optional<vector<uint8_t>> content =
             support::decryptAes128Gcm(storageKey_, encryptedContent, entryAdditionalData_);
     if (!content) {
@@ -647,12 +641,12 @@
         currentNameSpaceDeviceNameSpacesMap_.add(currentName_, std::move(entryValueItem));
     }
 
-    *outContent = byteStringToSigned(content.value());
+    *outContent = content.value();
     return ndk::ScopedAStatus::ok();
 }
 
-ndk::ScopedAStatus IdentityCredential::finishRetrieval(vector<int8_t>* outMac,
-                                                       vector<int8_t>* outDeviceNameSpaces) {
+ndk::ScopedAStatus IdentityCredential::finishRetrieval(vector<uint8_t>* outMac,
+                                                       vector<uint8_t>* outDeviceNameSpaces) {
     if (currentNameSpaceDeviceNameSpacesMap_.size() > 0) {
         deviceNameSpacesMap_.add(currentNameSpace_,
                                  std::move(currentNameSpaceDeviceNameSpacesMap_));
@@ -704,13 +698,13 @@
         }
     }
 
-    *outMac = byteStringToSigned(mac.value_or(vector<uint8_t>({})));
-    *outDeviceNameSpaces = byteStringToSigned(encodedDeviceNameSpaces);
+    *outMac = mac.value_or(vector<uint8_t>({}));
+    *outDeviceNameSpaces = encodedDeviceNameSpaces;
     return ndk::ScopedAStatus::ok();
 }
 
 ndk::ScopedAStatus IdentityCredential::generateSigningKeyPair(
-        vector<int8_t>* outSigningKeyBlob, Certificate* outSigningKeyCertificate) {
+        vector<uint8_t>* outSigningKeyBlob, Certificate* outSigningKeyCertificate) {
     string serialDecimal = "0";  // TODO: set serial to something unique
     string issuer = "Android Open Source Project";
     string subject = "Android IdentityCredential Reference Implementation";
@@ -758,9 +752,9 @@
         return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
                 IIdentityCredentialStore::STATUS_FAILED, "Error encrypting signingKey"));
     }
-    *outSigningKeyBlob = byteStringToSigned(encryptedSigningKey.value());
+    *outSigningKeyBlob = encryptedSigningKey.value();
     *outSigningKeyCertificate = Certificate();
-    outSigningKeyCertificate->encodedCertificate = byteStringToSigned(certificate.value());
+    outSigningKeyCertificate->encodedCertificate = certificate.value();
     return ndk::ScopedAStatus::ok();
 }