}

var cacheLRU = expirable.NewLRU[cacheKey, string](1000, nil, 15*time.Second)

func authenticateNode(accessKey, secretKey, audience string) (string, error) {
	claims := xjwt.NewStandardClaims()
	claims.SetExpiry(UTCNow().Add(defaultInterNodeJWTExpiry))
	claims.SetAccessKey(accessKey)
	claims.SetAudience(audience)

	jwt := jwtgo.NewWithClaims(jwtgo.SigningMethodHS512, claims)
	return jwt.SignedString([]byte(secretKey))
}