Implementing KMS can present several challenges. One common issue is the complexity of integrating KMS with existing systems and applications, which may require careful planning and technical expertise. Additionally, organizations must ensure that their staff is properly trained to manage keys and understand the security implications of key exposure. Another challenge is managing the lifecycle of encryption keys, including rotation and revocation, which can be a daunting task without a clear strategy in place. Finally, the cost of KMS solutions, especially for small businesses, can be a consideration, as they may need to balance security needs with budget constraints.