diff --git a/src/@types/basic.d.ts b/src/@types/basic.d.ts
index 03f9451..90f020e 100644
--- a/src/@types/basic.d.ts
+++ b/src/@types/basic.d.ts
@@ -1,8 +1,8 @@
-import {Buffer} from 'buffer';
+import { Buffer } from 'buffer'
 
-export type bytes = Buffer;
-export type bytes32 = Buffer;
-export type bytes16 = Buffer;
+export type bytes = Buffer
+export type bytes32 = Buffer
+export type bytes16 = Buffer
 
-export type uint32 = number;
-export type uint64 = number;
+export type uint32 = number
+export type uint64 = number
diff --git a/src/@types/handshake-interface.d.ts b/src/@types/handshake-interface.d.ts
index f432bda..748f64f 100644
--- a/src/@types/handshake-interface.d.ts
+++ b/src/@types/handshake-interface.d.ts
@@ -1,11 +1,11 @@
-import {bytes} from "./basic";
-import {NoiseSession} from "./handshake";
-import PeerId from "peer-id";
+import { bytes } from './basic'
+import { NoiseSession } from './handshake'
+import PeerId from 'peer-id'
 
 export interface IHandshake {
-  session: NoiseSession;
-  remotePeer: PeerId;
-  remoteEarlyData: Buffer;
-  encrypt(plaintext: bytes, session: NoiseSession): bytes;
-  decrypt(ciphertext: bytes, session: NoiseSession): {plaintext: bytes; valid: boolean};
+  session: NoiseSession
+  remotePeer: PeerId
+  remoteEarlyData: Buffer
+  encrypt: (plaintext: bytes, session: NoiseSession) => bytes
+  decrypt: (ciphertext: bytes, session: NoiseSession) => {plaintext: bytes, valid: boolean}
 }
diff --git a/src/@types/handshake.d.ts b/src/@types/handshake.d.ts
index 7e823b3..c6aa1cc 100644
--- a/src/@types/handshake.d.ts
+++ b/src/@types/handshake.d.ts
@@ -1,45 +1,45 @@
-import {bytes, bytes32, uint32, uint64} from "./basic";
-import {KeyPair} from "./libp2p";
+import { bytes, bytes32, uint32, uint64 } from './basic'
+import { KeyPair } from './libp2p'
 
-export type Hkdf = [bytes, bytes, bytes];
+export type Hkdf = [bytes, bytes, bytes]
 
-export type MessageBuffer = {
-  ne: bytes32;
-  ns: bytes;
-  ciphertext: bytes;
+export interface MessageBuffer {
+  ne: bytes32
+  ns: bytes
+  ciphertext: bytes
 }
 
-export type CipherState = {
-  k: bytes32;
-  n: uint32;
+export interface CipherState {
+  k: bytes32
+  n: uint32
 }
 
-export type SymmetricState = {
-  cs: CipherState;
-  ck: bytes32;  // chaining key
-  h: bytes32; // handshake hash
+export interface SymmetricState {
+  cs: CipherState
+  ck: bytes32 // chaining key
+  h: bytes32 // handshake hash
 }
 
-export type HandshakeState = {
-  ss: SymmetricState;
-  s: KeyPair;
-  e?: KeyPair;
-  rs: bytes32;
-  re: bytes32;
-  psk: bytes32;
+export interface HandshakeState {
+  ss: SymmetricState
+  s: KeyPair
+  e?: KeyPair
+  rs: bytes32
+  re: bytes32
+  psk: bytes32
 }
 
-export type NoiseSession = {
-  hs: HandshakeState;
-  h?: bytes32;
-  cs1?: CipherState;
-  cs2?: CipherState;
-  mc: uint64;
-  i: boolean;
+export interface NoiseSession {
+  hs: HandshakeState
+  h?: bytes32
+  cs1?: CipherState
+  cs2?: CipherState
+  mc: uint64
+  i: boolean
 }
 
 export interface INoisePayload {
-  identityKey: bytes;
-  identitySig: bytes;
-  data: bytes;
+  identityKey: bytes
+  identitySig: bytes
+  data: bytes
 }
diff --git a/src/@types/it-length-prefixed/index.d.ts b/src/@types/it-length-prefixed/index.d.ts
index 99de1ad..825f0cb 100644
--- a/src/@types/it-length-prefixed/index.d.ts
+++ b/src/@types/it-length-prefixed/index.d.ts
@@ -3,33 +3,33 @@ declare module 'it-length-prefixed' {
   import { Buffer } from 'buffer'
 
   interface LengthDecoderFunction {
-    (data: Buffer | BufferList): number;
-    bytes: number;
+    (data: Buffer | BufferList): number
+    bytes: number
   }
 
   interface LengthEncoderFunction {
-    (value: number, target: Buffer, offset: number): number|Buffer;
-    bytes: number;
+    (value: number, target: Buffer, offset: number): number|Buffer
+    bytes: number
   }
 
   interface Encoder {
-    (options?: Partial<{lengthEncoder: LengthEncoderFunction}>): AsyncGenerator<BufferList, Buffer>;
-    single: (chunk: Buffer, options?: Partial<{lengthEncoder: LengthEncoderFunction}>) => BufferList;
-    MIN_POOL_SIZE: number;
-    DEFAULT_POOL_SIZE: number;
+    (options?: Partial<{lengthEncoder: LengthEncoderFunction}>): AsyncGenerator<BufferList, Buffer>
+    single: (chunk: Buffer, options?: Partial<{lengthEncoder: LengthEncoderFunction}>) => BufferList
+    MIN_POOL_SIZE: number
+    DEFAULT_POOL_SIZE: number
   }
 
   interface DecoderOptions {
-    lengthDecoder: LengthDecoderFunction;
-    maxLengthLength: number;
-    maxDataLength: number;
+    lengthDecoder: LengthDecoderFunction
+    maxLengthLength: number
+    maxDataLength: number
   }
 
   interface Decoder {
-    (options?: Partial<DecoderOptions>): AsyncGenerator<BufferList, BufferList>;
-    fromReader: (reader: any, options?: Partial<DecoderOptions>) => BufferList;
-    MAX_LENGTH_LENGTH: number;
-    MAX_DATA_LENGTH: number;
+    (options?: Partial<DecoderOptions>): AsyncGenerator<BufferList, BufferList>
+    fromReader: (reader: any, options?: Partial<DecoderOptions>) => BufferList
+    MAX_LENGTH_LENGTH: number
+    MAX_DATA_LENGTH: number
   }
 
   export const encode: Encoder
diff --git a/src/@types/it-pair/index.d.ts b/src/@types/it-pair/index.d.ts
index 1f05d9b..e5cb214 100644
--- a/src/@types/it-pair/index.d.ts
+++ b/src/@types/it-pair/index.d.ts
@@ -1,8 +1,8 @@
 declare module 'it-pair' {
-  export type Duplex = [Stream, Stream];
+  export type Duplex = [Stream, Stream]
 
-  type Stream = {
-    sink(source: Iterable<any>): void;
-    source: Record<string, any>;
+  interface Stream {
+    sink: (source: Iterable<any>) => void
+    source: Record<string, any>
   }
 }
diff --git a/src/@types/libp2p.d.ts b/src/@types/libp2p.d.ts
index 3c02747..d442353 100644
--- a/src/@types/libp2p.d.ts
+++ b/src/@types/libp2p.d.ts
@@ -1,20 +1,19 @@
-import { bytes, bytes32 } from "./basic";
-import PeerId from "peer-id";
+import { bytes, bytes32 } from './basic'
+import PeerId from 'peer-id'
 
-export type KeyPair = {
-  publicKey: bytes32;
-  privateKey: bytes32;
+export interface KeyPair {
+  publicKey: bytes32
+  privateKey: bytes32
 }
 
 export interface INoiseConnection {
-  remoteEarlyData?(): bytes;
-  secureOutbound(localPeer: PeerId, insecure: any, remotePeer: PeerId): Promise<SecureOutbound>;
-  secureInbound(localPeer: PeerId, insecure: any, remotePeer: PeerId): Promise<SecureOutbound>;
+  remoteEarlyData?: () => bytes
+  secureOutbound: (localPeer: PeerId, insecure: any, remotePeer: PeerId) => Promise<SecureOutbound>
+  secureInbound: (localPeer: PeerId, insecure: any, remotePeer: PeerId) => Promise<SecureOutbound>
 }
 
-export type SecureOutbound = {
-  conn: any;
-  remoteEarlyData: Buffer;
-  remotePeer: PeerId;
+export interface SecureOutbound {
+  conn: any
+  remoteEarlyData: Buffer
+  remotePeer: PeerId
 }
-
diff --git a/src/crypto.ts b/src/crypto.ts
index 8e50f71..5e84d01 100644
--- a/src/crypto.ts
+++ b/src/crypto.ts
@@ -3,7 +3,7 @@ import { IHandshake } from './@types/handshake-interface'
 import { NOISE_MSG_MAX_LENGTH_BYTES, NOISE_MSG_MAX_LENGTH_BYTES_WITHOUT_TAG } from './constants'
 
 interface IReturnEncryptionWrapper {
-  (source: Iterable<Uint8Array>): AsyncIterableIterator<Uint8Array>;
+  (source: Iterable<Uint8Array>): AsyncIterableIterator<Uint8Array>
 }
 
 // Returns generator that encrypts payload from the user
diff --git a/src/errors.ts b/src/errors.ts
index 5738e3a..08082d5 100644
--- a/src/errors.ts
+++ b/src/errors.ts
@@ -1,7 +1,7 @@
 import BufferList from 'bl'
 
 export class FailedIKError extends Error {
-  public initialMsg: string|BufferList|Buffer;
+  public initialMsg: string|BufferList|Buffer
 
   constructor (initialMsg: string|BufferList|Buffer, message?: string) {
     super(message)
diff --git a/src/handshake-ik.ts b/src/handshake-ik.ts
index 4a76716..075c5c0 100644
--- a/src/handshake-ik.ts
+++ b/src/handshake-ik.ts
@@ -19,16 +19,16 @@ import {
 import PeerId from 'peer-id'
 
 export class IKHandshake implements IHandshake {
-  public isInitiator: boolean;
-  public session: NoiseSession;
-  public remotePeer!: PeerId;
-  public remoteEarlyData: Buffer;
+  public isInitiator: boolean
+  public session: NoiseSession
+  public remotePeer!: PeerId
+  public remoteEarlyData: Buffer
 
-  private payload: bytes;
-  private prologue: bytes32;
-  private staticKeypair: KeyPair;
-  private connection: WrappedConnection;
-  private ik: IK;
+  private readonly payload: bytes
+  private readonly prologue: bytes32
+  private readonly staticKeypair: KeyPair
+  private readonly connection: WrappedConnection
+  private readonly ik: IK
 
   constructor (
     isInitiator: boolean,
@@ -48,7 +48,7 @@ export class IKHandshake implements IHandshake {
     if (remotePeer) {
       this.remotePeer = remotePeer
     }
-    this.ik = handshake || new IK()
+    this.ik = handshake ?? new IK()
     this.session = this.ik.initSession(this.isInitiator, this.prologue, this.staticKeypair, remoteStaticKey)
     this.remoteEarlyData = Buffer.alloc(0)
   }
@@ -79,9 +79,10 @@ export class IKHandshake implements IHandshake {
         logger('IK Stage 0 - Responder successfully verified payload!')
         logRemoteEphemeralKey(this.session.hs.re)
       } catch (e) {
+        const err = e as Error
         logger('Responder breaking up with IK handshake in stage 0.')
 
-        throw new FailedIKError(receivedMsg, `Error occurred while verifying initiator's signed payload: ${e.message}`)
+        throw new FailedIKError(receivedMsg, `Error occurred while verifying initiator's signed payload: ${err.message}`)
       }
     }
   }
@@ -104,8 +105,9 @@ export class IKHandshake implements IHandshake {
         logger('IK Stage 1 - Initiator successfully verified payload!')
         logRemoteEphemeralKey(this.session.hs.re)
       } catch (e) {
+        const err = e as Error
         logger('Initiator breaking up with IK handshake in stage 1.')
-        throw new FailedIKError(receivedMsg, `Error occurred while verifying responder's signed payload: ${e.message}`)
+        throw new FailedIKError(receivedMsg, `Error occurred while verifying responder's signed payload: ${err.message}`)
       }
     } else {
       logger('IK Stage 1 - Responder sending message...')
@@ -117,7 +119,7 @@ export class IKHandshake implements IHandshake {
     logCipherState(this.session)
   }
 
-  public decrypt (ciphertext: bytes, session: NoiseSession): {plaintext: bytes; valid: boolean} {
+  public decrypt (ciphertext: bytes, session: NoiseSession): {plaintext: bytes, valid: boolean} {
     const cs = this.getCS(session, false)
     return this.ik.decryptWithAd(cs, Buffer.alloc(0), ciphertext)
   }
diff --git a/src/handshake-xx-fallback.ts b/src/handshake-xx-fallback.ts
index 10a08a1..748151b 100644
--- a/src/handshake-xx-fallback.ts
+++ b/src/handshake-xx-fallback.ts
@@ -10,8 +10,8 @@ import { decode0, decode1 } from './encoder'
 import PeerId from 'peer-id'
 
 export class XXFallbackHandshake extends XXHandshake {
-  private ephemeralKeys?: KeyPair;
-  private initialMsg: bytes;
+  private readonly ephemeralKeys?: KeyPair
+  private readonly initialMsg: bytes
 
   constructor (
     isInitiator: boolean,
@@ -73,7 +73,8 @@ export class XXFallbackHandshake extends XXHandshake {
         await verifySignedPayload(this.session.hs.rs, decodedPayload, this.remotePeer)
         this.setRemoteEarlyData(decodedPayload.data)
       } catch (e) {
-        throw new Error(`Error occurred while verifying signed payload from responder: ${e.message}`)
+        const err = e as Error
+        throw new Error(`Error occurred while verifying signed payload from responder: ${err.message}`)
       }
       logger('All good with the signature!')
     } else {
diff --git a/src/handshake-xx.ts b/src/handshake-xx.ts
index ba1bbef..91de7fa 100644
--- a/src/handshake-xx.ts
+++ b/src/handshake-xx.ts
@@ -23,17 +23,17 @@ import { WrappedConnection } from './noise'
 import PeerId from 'peer-id'
 
 export class XXHandshake implements IHandshake {
-  public isInitiator: boolean;
-  public session: NoiseSession;
-  public remotePeer!: PeerId;
-  public remoteEarlyData: Buffer;
+  public isInitiator: boolean
+  public session: NoiseSession
+  public remotePeer!: PeerId
+  public remoteEarlyData: Buffer
 
-  protected payload: bytes;
-  protected connection: WrappedConnection;
-  protected xx: XX;
-  protected staticKeypair: KeyPair;
+  protected payload: bytes
+  protected connection: WrappedConnection
+  protected xx: XX
+  protected staticKeypair: KeyPair
 
-  private prologue: bytes32;
+  private readonly prologue: bytes32
 
   constructor (
     isInitiator: boolean,
@@ -52,7 +52,7 @@ export class XXHandshake implements IHandshake {
     if (remotePeer) {
       this.remotePeer = remotePeer
     }
-    this.xx = handshake || new XX()
+    this.xx = handshake ?? new XX()
     this.session = this.xx.initSession(this.isInitiator, this.prologue, this.staticKeypair)
     this.remoteEarlyData = Buffer.alloc(0)
   }
@@ -98,7 +98,8 @@ export class XXHandshake implements IHandshake {
         this.remotePeer = await verifySignedPayload(receivedMessageBuffer.ns, decodedPayload, this.remotePeer)
         this.setRemoteEarlyData(decodedPayload.data)
       } catch (e) {
-        throw new Error(`Error occurred while verifying signed payload: ${e.message}`)
+        const err = e as Error
+        throw new Error(`Error occurred while verifying signed payload: ${err.message}`)
       }
       logger('All good with the signature!')
     } else {
@@ -132,7 +133,8 @@ export class XXHandshake implements IHandshake {
         await verifySignedPayload(this.session.hs.rs, decodedPayload, this.remotePeer)
         this.setRemoteEarlyData(decodedPayload.data)
       } catch (e) {
-        throw new Error(`Error occurred while verifying signed payload: ${e.message}`)
+        const err = e as Error
+        throw new Error(`Error occurred while verifying signed payload: ${err.message}`)
       }
     }
     logCipherState(this.session)
@@ -144,7 +146,7 @@ export class XXHandshake implements IHandshake {
     return this.xx.encryptWithAd(cs, Buffer.alloc(0), plaintext)
   }
 
-  public decrypt (ciphertext: bytes, session: NoiseSession): {plaintext: bytes; valid: boolean} {
+  public decrypt (ciphertext: bytes, session: NoiseSession): {plaintext: bytes, valid: boolean} {
     const cs = this.getCS(session, false)
     return this.xx.decryptWithAd(cs, Buffer.alloc(0), ciphertext)
   }
diff --git a/src/handshakes/abstract-handshake.ts b/src/handshakes/abstract-handshake.ts
index 275152b..98301f1 100644
--- a/src/handshakes/abstract-handshake.ts
+++ b/src/handshakes/abstract-handshake.ts
@@ -18,7 +18,7 @@ export abstract class AbstractHandshake {
     return e
   }
 
-  public decryptWithAd (cs: CipherState, ad: bytes, ciphertext: bytes): {plaintext: bytes; valid: boolean} {
+  public decryptWithAd (cs: CipherState, ad: bytes, ciphertext: bytes): {plaintext: bytes, valid: boolean} {
     const { plaintext, valid } = this.decrypt(cs.k, cs.n, ad, ciphertext)
     this.setNonce(cs, this.incrementNonce(cs.n))
 
@@ -78,7 +78,7 @@ export abstract class AbstractHandshake {
     return ciphertext
   }
 
-  protected decrypt (k: bytes32, n: uint32, ad: bytes, ciphertext: bytes): {plaintext: bytes; valid: boolean} {
+  protected decrypt (k: bytes32, n: uint32, ad: bytes, ciphertext: bytes): {plaintext: bytes, valid: boolean} {
     const nonce = this.nonceToBytes(n)
     const ctx = new AEAD()
     ciphertext = Buffer.from(ciphertext)
@@ -91,7 +91,7 @@ export abstract class AbstractHandshake {
     return { plaintext: ciphertext, valid: ctx.verify(tag) }
   }
 
-  protected decryptAndHash (ss: SymmetricState, ciphertext: bytes): {plaintext: bytes; valid: boolean} {
+  protected decryptAndHash (ss: SymmetricState, ciphertext: bytes): {plaintext: bytes, valid: boolean} {
     let plaintext: bytes; let valid = true
     if (this.hasKey(ss.cs)) {
       ({ plaintext, valid } = this.decryptWithAd(ss.cs, ss.h, ciphertext))
@@ -125,7 +125,7 @@ export abstract class AbstractHandshake {
 
   protected mixKey (ss: SymmetricState, ikm: bytes32): void {
     const [ck, tempK] = getHkdf(ss.ck, ikm)
-    ss.cs = this.initializeKey(tempK) as CipherState
+    ss.cs = this.initializeKey(tempK)
     ss.ck = ck
   }
 
@@ -173,7 +173,7 @@ export abstract class AbstractHandshake {
     return { ne, ns, ciphertext }
   }
 
-  protected readMessageRegular (cs: CipherState, message: MessageBuffer): {plaintext: bytes; valid: boolean} {
+  protected readMessageRegular (cs: CipherState, message: MessageBuffer): {plaintext: bytes, valid: boolean} {
     return this.decryptWithAd(cs, Buffer.alloc(0), message.ciphertext)
   }
 }
diff --git a/src/handshakes/ik.ts b/src/handshakes/ik.ts
index c57797d..10816c9 100644
--- a/src/handshakes/ik.ts
+++ b/src/handshakes/ik.ts
@@ -55,7 +55,7 @@ export class IK extends AbstractHandshake {
     return messageBuffer
   }
 
-  public recvMessage (session: NoiseSession, message: MessageBuffer): {plaintext: bytes; valid: boolean} {
+  public recvMessage (session: NoiseSession, message: MessageBuffer): {plaintext: bytes, valid: boolean} {
     let plaintext = Buffer.alloc(0); let valid = false
     if (session.mc === 0) {
       ({ plaintext, valid } = this.readMessageA(session.hs, message))
@@ -101,7 +101,7 @@ export class IK extends AbstractHandshake {
     return { messageBuffer, cs1, cs2, h: hs.ss.h }
   }
 
-  private readMessageA (hs: HandshakeState, message: MessageBuffer): {plaintext: bytes; valid: boolean} {
+  private readMessageA (hs: HandshakeState, message: MessageBuffer): {plaintext: bytes, valid: boolean} {
     if (isValidPublicKey(message.ne)) {
       hs.re = message.ne
     }
@@ -117,7 +117,7 @@ export class IK extends AbstractHandshake {
     return { plaintext, valid: (valid1 && valid2) }
   }
 
-  private readMessageB (hs: HandshakeState, message: MessageBuffer): {h: bytes; plaintext: bytes; valid: boolean; cs1: CipherState; cs2: CipherState} {
+  private readMessageB (hs: HandshakeState, message: MessageBuffer): {h: bytes, plaintext: bytes, valid: boolean, cs1: CipherState, cs2: CipherState} {
     if (isValidPublicKey(message.ne)) {
       hs.re = message.ne
     }
diff --git a/src/handshakes/xx.ts b/src/handshakes/xx.ts
index 1a09218..e7bbdb9 100644
--- a/src/handshakes/xx.ts
+++ b/src/handshakes/xx.ts
@@ -27,7 +27,7 @@ export class XX extends AbstractHandshake {
   private writeMessageA (hs: HandshakeState, payload: bytes, e?: KeyPair): MessageBuffer {
     const ns = Buffer.alloc(0)
 
-    if (e) {
+    if (e !== undefined) {
       hs.e = e
     } else {
       hs.e = generateKeypair()
@@ -68,7 +68,7 @@ export class XX extends AbstractHandshake {
     return { h: hs.ss.h, messageBuffer, cs1, cs2 }
   }
 
-  private readMessageA (hs: HandshakeState, message: MessageBuffer): {plaintext: bytes; valid: boolean} {
+  private readMessageA (hs: HandshakeState, message: MessageBuffer): {plaintext: bytes, valid: boolean} {
     if (isValidPublicKey(message.ne)) {
       hs.re = message.ne
     }
@@ -77,7 +77,7 @@ export class XX extends AbstractHandshake {
     return this.decryptAndHash(hs.ss, message.ciphertext)
   }
 
-  private readMessageB (hs: HandshakeState, message: MessageBuffer): {plaintext: bytes; valid: boolean} {
+  private readMessageB (hs: HandshakeState, message: MessageBuffer): {plaintext: bytes, valid: boolean} {
     if (isValidPublicKey(message.ne)) {
       hs.re = message.ne
     }
@@ -96,7 +96,7 @@ export class XX extends AbstractHandshake {
     return { plaintext, valid: (valid1 && valid2) }
   }
 
-  private readMessageC (hs: HandshakeState, message: MessageBuffer): {h: bytes; plaintext: bytes; valid: boolean; cs1: CipherState; cs2: CipherState} {
+  private readMessageC (hs: HandshakeState, message: MessageBuffer): {h: bytes, plaintext: bytes, valid: boolean, cs1: CipherState, cs2: CipherState} {
     const { plaintext: ns, valid: valid1 } = this.decryptAndHash(hs.ss, message.ns)
     if (valid1 && ns.length === 32 && isValidPublicKey(ns)) {
       hs.rs = ns
@@ -164,7 +164,7 @@ export class XX extends AbstractHandshake {
     return messageBuffer
   }
 
-  public recvMessage (session: NoiseSession, message: MessageBuffer): {plaintext: bytes; valid: boolean} {
+  public recvMessage (session: NoiseSession, message: MessageBuffer): {plaintext: bytes, valid: boolean} {
     let plaintext: bytes = Buffer.alloc(0)
     let valid = false
     if (session.mc === 0) {
diff --git a/src/keycache.ts b/src/keycache.ts
index 820161a..9261cda 100644
--- a/src/keycache.ts
+++ b/src/keycache.ts
@@ -5,7 +5,7 @@ import PeerId from 'peer-id'
  * Storage for static keys of previously connected peers.
  */
 class Keycache {
-  private storage = new Map<Uint8Array, bytes32>();
+  private readonly storage = new Map<Uint8Array, bytes32>()
 
   public store (peerId: PeerId, key: bytes32): void {
     this.storage.set(peerId.id, key)
@@ -15,7 +15,7 @@ class Keycache {
     if (!peerId) {
       return null
     }
-    return this.storage.get(peerId.id) || null
+    return this.storage.get(peerId.id) ?? null
   }
 
   public resetStorage (): void {
diff --git a/src/noise.ts b/src/noise.ts
index e189bd1..d8b4a24 100644
--- a/src/noise.ts
+++ b/src/noise.ts
@@ -21,22 +21,22 @@ import { logger } from './logger'
 import PeerId from 'peer-id'
 import { NOISE_MSG_MAX_LENGTH_BYTES } from './constants'
 
-export type WrappedConnection = ReturnType<typeof Wrap>;
+export type WrappedConnection = ReturnType<typeof Wrap>
 
-type HandshakeParams = {
-  connection: WrappedConnection;
-  isInitiator: boolean;
-  localPeer: PeerId;
-  remotePeer?: PeerId;
-};
+interface HandshakeParams {
+  connection: WrappedConnection
+  isInitiator: boolean
+  localPeer: PeerId
+  remotePeer?: PeerId
+}
 
 export class Noise implements INoiseConnection {
-  public protocol = '/noise';
+  public protocol = '/noise'
 
-  private readonly prologue = Buffer.alloc(0);
-  private readonly staticKeys: KeyPair;
-  private readonly earlyData?: bytes;
-  private useNoisePipes: boolean;
+  private readonly prologue = Buffer.alloc(0)
+  private readonly staticKeys: KeyPair
+  private readonly earlyData?: bytes
+  private readonly useNoisePipes: boolean
 
   /**
    *
@@ -44,7 +44,7 @@ export class Noise implements INoiseConnection {
    * @param {bytes} earlyData
    */
   constructor (staticNoiseKey?: bytes, earlyData?: bytes) {
-    this.earlyData = earlyData || Buffer.alloc(0)
+    this.earlyData = earlyData ?? Buffer.alloc(0)
     // disabled until properly specked
     this.useNoisePipes = false
 
@@ -71,9 +71,6 @@ export class Noise implements INoiseConnection {
     const wrappedConnection = Wrap(
       connection,
       {
-        // wrong types in repo
-        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
-        // @ts-ignore
         lengthEncoder: uint16BEEncode,
         lengthDecoder: uint16BEDecode,
         maxDataLength: NOISE_MSG_MAX_LENGTH_BYTES
@@ -106,9 +103,6 @@ export class Noise implements INoiseConnection {
     const wrappedConnection = Wrap(
       connection,
       {
-        // wrong types in repo
-        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
-        // @ts-ignore
         lengthEncoder: uint16BEEncode,
         lengthDecoder: uint16BEDecode,
         maxDataLength: NOISE_MSG_MAX_LENGTH_BYTES
@@ -153,7 +147,7 @@ export class Noise implements INoiseConnection {
         this.staticKeys,
         connection,
         // safe to cast as we did checks
-        KeyCache.load(params.remotePeer) || Buffer.alloc(32),
+        KeyCache.load(params.remotePeer) ?? Buffer.alloc(32),
         remotePeer as PeerId
       )
 
@@ -189,7 +183,8 @@ export class Noise implements INoiseConnection {
       await handshake.finish()
     } catch (e) {
       logger(e)
-      throw new Error(`Error occurred during XX Fallback handshake: ${e.message}`)
+      const err = e as Error
+      throw new Error(`Error occurred during XX Fallback handshake: ${err.message}`)
     }
 
     return handshake
@@ -211,7 +206,8 @@ export class Noise implements INoiseConnection {
         KeyCache.store(handshake.remotePeer, handshake.getRemoteStaticKey())
       }
     } catch (e) {
-      throw new Error(`Error occurred during XX handshake: ${e.message}`)
+      const err = e as Error
+      throw new Error(`Error occurred during XX handshake: ${err.message}`)
     }
 
     return handshake
diff --git a/src/utils.ts b/src/utils.ts
index 5413c13..700c3bc 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -28,9 +28,9 @@ export async function getPayload (
   earlyData?: bytes
 ): Promise<bytes> {
   const signedPayload = await signPayload(localPeer, getHandshakePayload(staticPublicKey))
-  const earlyDataPayload = earlyData || Buffer.alloc(0)
+  const earlyDataPayload = earlyData ?? Buffer.alloc(0)
 
-  return await createHandshakePayload(
+  return createHandshakePayload(
     localPeer.marshalPubKey(),
     signedPayload,
     earlyDataPayload
@@ -45,7 +45,7 @@ export function createHandshakePayload (
   const payloadInit = NoiseHandshakePayloadProto.create({
     identityKey: Buffer.from(libp2pPublicKey),
     identitySig: signedPayload,
-    data: earlyData || null
+    data: earlyData ?? null
   })
 
   return Buffer.from(NoiseHandshakePayloadProto.encode(payloadInit).finish())
@@ -94,10 +94,12 @@ export async function verifySignedPayload (
   const generatedPayload = getHandshakePayload(noiseStaticKey)
   // Unmarshaling from PublicKey protobuf
   const publicKey = keys.unmarshalPublicKey(identityKey)
+  // TODO remove this after libp2p-crypto ships proper types
+  // eslint-disable-next-line @typescript-eslint/no-misused-promises
   if (!payload.identitySig || !publicKey.verify(generatedPayload, Buffer.from(payload.identitySig))) {
     throw new Error("Static key doesn't match to peer that signed payload!")
   }
-  return PeerId.createFromPubKey(identityKey)
+  return await PeerId.createFromPubKey(identityKey)
 }
 
 export function getHkdf (ck: bytes32, ikm: bytes): Hkdf {
diff --git a/test/fixtures/peer.ts b/test/fixtures/peer.ts
index 15f394a..e87be60 100644
--- a/test/fixtures/peer.ts
+++ b/test/fixtures/peer.ts
@@ -19,9 +19,9 @@ const peers = [{
   pubKey: 'CAESIMbnikZaPciAMZhUXqDRVCs7VFOBtmlIk26g0GgOotDA'
 }]
 
-export async function createPeerIdsFromFixtures (length:number): Promise<PeerId[]> {
+export async function createPeerIdsFromFixtures (length: number): Promise<PeerId[]> {
   return await Promise.all(
-    Array.from({ length }).map((_, i) => PeerId.createFromJSON(peers[i]))
+    Array.from({ length }).map(async (_, i) => await PeerId.createFromJSON(peers[i]))
   )
 }
 
diff --git a/test/handshakes/ik.spec.ts b/test/handshakes/ik.spec.ts
index f33eb54..bad467f 100644
--- a/test/handshakes/ik.spec.ts
+++ b/test/handshakes/ik.spec.ts
@@ -56,8 +56,8 @@ describe('IK handshake', () => {
       // initiator receives message
       ikI.recvMessage(initiatorSession, messageBuffer2)
 
-      assert(initiatorSession?.cs1?.k.equals(responderSession?.cs1?.k || new Uint8Array()))
-      assert(initiatorSession?.cs2?.k.equals(responderSession?.cs2?.k || new Uint8Array()))
+      assert(initiatorSession?.cs1?.k.equals(responderSession?.cs1?.k ?? new Uint8Array()))
+      assert(initiatorSession?.cs2?.k.equals(responderSession?.cs2?.k ?? new Uint8Array()))
     } catch (e) {
       return assert(false, e.message)
     }
diff --git a/test/keycache.spec.ts b/test/keycache.spec.ts
index e1a3c32..0bd1056 100644
--- a/test/keycache.spec.ts
+++ b/test/keycache.spec.ts
@@ -15,9 +15,10 @@ describe('KeyCache', () => {
       const key = Buffer.from('this is id 007')
       await KeyCache.store(peerA, key)
       const result = await KeyCache.load(peerA)
-      assert(uint8ArrayEquals(result, key), 'Stored and loaded key are not the same')
+      assert(result !== null && uint8ArrayEquals(result, key), 'Stored and loaded key are not the same')
     } catch (e) {
-      assert(false, `Test failed - ${e.message}`)
+      const err = e as Error
+      assert(false, `Test failed - ${err.message}`)
     }
   })
 
@@ -25,9 +26,10 @@ describe('KeyCache', () => {
     try {
       const [newPeer] = await createPeerIds(1)
       const result = await KeyCache.load(newPeer)
-      assert(!result)
+      assert(result === null)
     } catch (e) {
-      assert(false, `Test failed - ${e.message}`)
+      const err = e as Error
+      assert(false, `Test failed - ${err.message}`)
     }
   })
 })
diff --git a/test/utils.ts b/test/utils.ts
index 4042ef9..4f0eab5 100644
--- a/test/utils.ts
+++ b/test/utils.ts
@@ -8,7 +8,7 @@ export async function generateEd25519Keys (): Promise<PrivateKey> {
 
 export function getKeyPairFromPeerId (peerId: PeerId): KeyPair {
   return {
-    privateKey: peerId.privKey.marshal().slice(0, 32),
-    publicKey: peerId.marshalPubKey()
+    privateKey: Buffer.from(peerId.privKey.marshal().slice(0, 32)),
+    publicKey: Buffer.from(peerId.marshalPubKey())
   }
 }
diff --git a/test/xx-fallback-handshake.spec.ts b/test/xx-fallback-handshake.spec.ts
index 6dabb02..4f42336 100644
--- a/test/xx-fallback-handshake.spec.ts
+++ b/test/xx-fallback-handshake.spec.ts
@@ -48,7 +48,7 @@ describe('XX Fallback Handshake', () => {
       // This is the point where initiator falls back from IK
       const initialMsgI = await connectionFrom.readLP()
       const handshakeInit =
-        new XXFallbackHandshake(true, handshakePayload, prologue, staticKeysInitiator, connectionFrom, initialMsgI, peerB, ephemeralKeys)
+        new XXFallbackHandshake(true, handshakePayload, prologue, staticKeysInitiator, connectionFrom, initialMsgI.slice(0), peerB, ephemeralKeys)
 
       await handshakeInit.propose()
       await handshakeInit.exchange()
@@ -60,7 +60,10 @@ describe('XX Fallback Handshake', () => {
       const sessionResponder = handshakeResp.session
 
       // Test shared key
-      if (sessionInitator.cs1 && sessionResponder.cs1 && sessionInitator.cs2 && sessionResponder.cs2) {
+      if (sessionInitator.cs1 !== undefined &&
+        sessionResponder.cs1 !== undefined &&
+        sessionInitator.cs2 !== undefined &&
+        sessionResponder.cs2 !== undefined) {
         assert(sessionInitator.cs1.k.equals(sessionResponder.cs1.k))
         assert(sessionInitator.cs2.k.equals(sessionResponder.cs2.k))
       } else {