diff --git a/src/blst/publicKey.ts b/src/blst/publicKey.ts
index 187e191..39c3684 100644
--- a/src/blst/publicKey.ts
+++ b/src/blst/publicKey.ts
@@ -1,5 +1,5 @@
 import * as blst from "@chainsafe/blst";
-import {ZeroPublicKeyError} from "../errors";
+import {EmptyAggregateError, ZeroPublicKeyError} from "../errors";
 import {bytesToHex, hexToBytes} from "../helpers";
 import {IPublicKey} from "../interface";
 
@@ -27,6 +27,10 @@ export class PublicKey implements IPublicKey {
   }
 
   static aggregate(pubkeys: PublicKey[]): PublicKey {
+    if (pubkeys.length === 0) {
+      throw new EmptyAggregateError();
+    }
+
     const jacobian = blst.aggregatePubkeys(pubkeys.map((pk) => pk.jacobian));
     const affine = jacobian.toPublicKey();
     return new PublicKey(affine, jacobian);
diff --git a/src/blst/signature.ts b/src/blst/signature.ts
index de4379a..3a476fd 100644
--- a/src/blst/signature.ts
+++ b/src/blst/signature.ts
@@ -2,7 +2,7 @@ import * as blst from "@chainsafe/blst";
 import {bytesToHex, hexToBytes} from "../helpers";
 import {ISignature} from "../interface";
 import {PublicKey} from "./publicKey";
-import {ZeroSignatureError} from "../errors";
+import {EmptyAggregateError, ZeroSignatureError} from "../errors";
 
 export class Signature implements ISignature {
   readonly affine: blst.Signature;
@@ -12,12 +12,7 @@ export class Signature implements ISignature {
   }
 
   static fromBytes(bytes: Uint8Array): Signature {
-    const affine = blst.Signature.fromBytes(bytes);
-    if (affine.value.is_inf()) {
-      throw new ZeroSignatureError();
-    }
-
-    return new Signature(affine);
+    return new Signature(blst.Signature.fromBytes(bytes));
   }
 
   static fromHex(hex: string): Signature {
@@ -25,11 +20,20 @@ export class Signature implements ISignature {
   }
 
   static aggregate(signatures: Signature[]): Signature {
+    if (signatures.length === 0) {
+      throw new EmptyAggregateError();
+    }
+
     const agg = blst.AggregateSignature.fromSignatures(signatures.map((sig) => sig.affine));
     return new Signature(agg.toSignature());
   }
 
   verify(publicKey: PublicKey, message: Uint8Array): boolean {
+    // Individual infinity signatures are NOT okay. Aggregated signatures MAY be infinity
+    if (this.affine.value.is_inf()) {
+      throw new ZeroSignatureError();
+    }
+
     return this.aggregateVerify([message], [publicKey.affine]);
   }
 
diff --git a/src/errors.ts b/src/errors.ts
index 80ff3fc..58ac7b2 100644
--- a/src/errors.ts
+++ b/src/errors.ts
@@ -1,23 +1,45 @@
 /**
- * Indicate that this error is expected and should not be ignored
- * by the functional interface try / catch blocks
+ * This error should not be ignored by the functional interface
+ * try / catch blocks, to prevent false negatives
  */
-export class ExpectedError extends Error {}
+export class NotInitializedError extends Error {
+  constructor(implementation: string) {
+    super(`NOT_INITIALIZED: ${implementation}`);
+  }
+}
 
 export class ZeroPrivateKeyError extends Error {
   constructor() {
-    super("PRIVATE_KEY_IS_ZERO");
+    super("ZERO_PRIVATE_KEY");
   }
 }
 
 export class ZeroPublicKeyError extends Error {
   constructor() {
-    super("PUBLIC_KEY_IS_ZERO");
+    super("ZERO_PUBLIC_KEY");
   }
 }
 
 export class ZeroSignatureError extends Error {
   constructor() {
-    super("SIGNATURE_IS_ZERO");
+    super("ZERO_SIGNATURE");
+  }
+}
+
+export class EmptyAggregateError extends Error {
+  constructor() {
+    super("EMPTY_AGGREGATE_ARRAY");
+  }
+}
+
+export class InvalidOrderError extends Error {
+  constructor() {
+    super("INVALID_ORDER");
+  }
+}
+
+export class InvalidLengthError extends Error {
+  constructor(arg: string, length: number) {
+    super(`INVALID_LENGTH: ${arg} must have ${length} bytes`);
   }
 }
diff --git a/src/functional.ts b/src/functional.ts
index da7ad41..a731a7d 100644
--- a/src/functional.ts
+++ b/src/functional.ts
@@ -1,6 +1,6 @@
 import {IBls} from "./interface";
 import {validateBytes} from "./helpers";
-import {ExpectedError} from "./errors";
+import {NotInitializedError} from "./errors";
 
 // Returned type is enforced at each implementation's index
 // eslint-disable-next-line @typescript-eslint/explicit-function-return-type
@@ -54,7 +54,7 @@ export function functionalInterfaceFactory({
     try {
       return Signature.fromBytes(signature).verify(PublicKey.fromBytes(publicKey), message);
     } catch (e) {
-      if (e instanceof ExpectedError) throw e;
+      if (e instanceof NotInitializedError) throw e;
       return false;
     }
   }
@@ -76,7 +76,7 @@ export function functionalInterfaceFactory({
         message
       );
     } catch (e) {
-      if (e instanceof ExpectedError) throw e;
+      if (e instanceof NotInitializedError) throw e;
       return false;
     }
   }
@@ -102,7 +102,7 @@ export function functionalInterfaceFactory({
         messages.map((msg) => msg)
       );
     } catch (e) {
-      if (e instanceof ExpectedError) throw e;
+      if (e instanceof NotInitializedError) throw e;
       return false;
     }
   }
diff --git a/src/herumi/context.ts b/src/herumi/context.ts
index b4da52e..7780283 100644
--- a/src/herumi/context.ts
+++ b/src/herumi/context.ts
@@ -1,6 +1,6 @@
 /* eslint-disable require-atomic-updates */
 import bls from "bls-eth-wasm";
-import {ExpectedError} from "../errors";
+import {NotInitializedError} from "../errors";
 
 type Bls = typeof bls;
 let blsGlobal: Bls | null = null;
@@ -28,7 +28,7 @@ export function destroy(): void {
 
 export function getContext(): Bls {
   if (!blsGlobal) {
-    throw new ExpectedError("BLS not initialized");
+    throw new NotInitializedError("herumi");
   }
   return blsGlobal;
 }
diff --git a/src/herumi/privateKey.ts b/src/herumi/privateKey.ts
index cfa5438..7eb9df6 100644
--- a/src/herumi/privateKey.ts
+++ b/src/herumi/privateKey.ts
@@ -6,7 +6,7 @@ import {PublicKey} from "./publicKey";
 import {Signature} from "./signature";
 import {bytesToHex, hexToBytes} from "../helpers";
 import {IPrivateKey} from "../interface";
-import {ZeroPrivateKeyError} from "../errors";
+import {InvalidLengthError, ZeroPrivateKeyError} from "../errors";
 
 export class PrivateKey implements IPrivateKey {
   readonly value: SecretKeyType;
@@ -21,7 +21,7 @@ export class PrivateKey implements IPrivateKey {
 
   static fromBytes(bytes: Uint8Array): PrivateKey {
     if (bytes.length !== SECRET_KEY_LENGTH) {
-      throw Error(`Private key should have ${SECRET_KEY_LENGTH} bytes`);
+      throw new InvalidLengthError("PrivateKey", SECRET_KEY_LENGTH);
     }
 
     const context = getContext();
diff --git a/src/herumi/publicKey.ts b/src/herumi/publicKey.ts
index 9fdf543..34c8338 100644
--- a/src/herumi/publicKey.ts
+++ b/src/herumi/publicKey.ts
@@ -3,7 +3,7 @@ import {getContext} from "./context";
 import {PUBLIC_KEY_LENGTH} from "../constants";
 import {bytesToHex, hexToBytes, isZeroUint8Array} from "../helpers";
 import {IPublicKey} from "../interface";
-import {ZeroPublicKeyError} from "../errors";
+import {EmptyAggregateError, InvalidLengthError, ZeroPublicKeyError} from "../errors";
 
 export class PublicKey implements IPublicKey {
   readonly value: PublicKeyType;
@@ -18,7 +18,7 @@ export class PublicKey implements IPublicKey {
 
   static fromBytes(bytes: Uint8Array): PublicKey {
     if (bytes.length !== PUBLIC_KEY_LENGTH) {
-      throw Error(`Public key must have ${PUBLIC_KEY_LENGTH} bytes`);
+      throw new InvalidLengthError("PublicKey", PUBLIC_KEY_LENGTH);
     }
 
     const context = getContext();
@@ -35,7 +35,7 @@ export class PublicKey implements IPublicKey {
 
   static aggregate(pubkeys: PublicKey[]): PublicKey {
     if (pubkeys.length === 0) {
-      throw Error("EMPTY_AGGREGATE_ARRAY");
+      throw new EmptyAggregateError();
     }
 
     const agg = new PublicKey(pubkeys[0].value.clone());
diff --git a/src/herumi/signature.ts b/src/herumi/signature.ts
index cf4fa32..ad0df9f 100644
--- a/src/herumi/signature.ts
+++ b/src/herumi/signature.ts
@@ -4,13 +4,14 @@ import {getContext} from "./context";
 import {PublicKey} from "./publicKey";
 import {bytesToHex, hexToBytes, isZeroUint8Array} from "../helpers";
 import {ISignature} from "../interface";
+import {EmptyAggregateError, InvalidLengthError, InvalidOrderError} from "../errors";
 
 export class Signature implements ISignature {
   readonly value: SignatureType;
 
   constructor(value: SignatureType) {
     if (!value.isValidOrder()) {
-      throw Error("Signature is not in valid order");
+      throw new InvalidOrderError();
     }
 
     this.value = value;
@@ -18,7 +19,7 @@ export class Signature implements ISignature {
 
   static fromBytes(bytes: Uint8Array): Signature {
     if (bytes.length !== SIGNATURE_LENGTH) {
-      throw Error(`Signature must have ${SIGNATURE_LENGTH} bytes`);
+      throw new InvalidLengthError("Signature", SIGNATURE_LENGTH);
     }
 
     const context = getContext();
@@ -35,7 +36,7 @@ export class Signature implements ISignature {
 
   static aggregate(signatures: Signature[]): Signature {
     if (signatures.length === 0) {
-      throw Error("EMPTY_AGGREGATE_ARRAY");
+      throw new EmptyAggregateError();
     }
 
     const context = getContext();
diff --git a/test/spec/aggregate.test.ts b/test/spec/aggregate.test.ts
index a825e74..f7b6277 100644
--- a/test/spec/aggregate.test.ts
+++ b/test/spec/aggregate.test.ts
@@ -3,6 +3,7 @@ import {describeDirectorySpecTest, InputType} from "@chainsafe/lodestar-spec-tes
 import {bytesToHex, hexToBytes} from "../../src/helpers";
 import {SPEC_TESTS_DIR} from "../params";
 import {describeForAllImplementations} from "../switch";
+import {EmptyAggregateError, ZeroSignatureError} from "../../src/errors";
 
 interface IAggregateSigsTestCase {
   data: {
@@ -21,7 +22,7 @@ describeForAllImplementations((bls) => {
         const agg = bls.aggregateSignatures(signatures.map(hexToBytes));
         return bytesToHex(agg);
       } catch (e) {
-        if (e.message === "EMPTY_AGGREGATE_ARRAY") return null;
+        if (e instanceof EmptyAggregateError) return null;
         throw e;
       }
     },