Knowledge

ERROR_IPSEC_IKE_INVALID_ENCRYPT_ALG - 13873 (0x3631)

Invalid encryption algorithm.

Updated: Feb 21, 2026

Technical Background

The ERROR_IPSEC_IKE_INVALID_ENCRYPT_ALG error is a specific error code related to the Internet Protocol Security (IPsec) and Internet Key Exchange (IKE) protocols in Windows. This error indicates that an invalid encryption algorithm was specified during the configuration of IPsec/IKE settings.

Error Details

The numeric value 13873 corresponds to the hexadecimal value 0x3631. The short description for this error is 'Invalid encryption algorithm'.

Common Causes

This error typically occurs when an unsupported or invalid encryption algorithm is specified in the IPsec/IKE configuration. This can be due to several factors, including:

  • Specifying a non-existent or deprecated encryption algorithm.
  • Configuring settings that are not compatible with the current version of Windows or the installed software stack.

Real-World Context

IPsec and IKE are critical components for secure communication over IP networks. They provide mechanisms for securing data transmission, including encryption to protect against eavesdropping and tampering. The ERROR_IPSEC_IKE_INVALID_ENCRYPT_ALG error can occur during the setup or configuration of these protocols.

Is This Error Critical?

The severity of this error depends on the context in which it occurs. If IPsec/IKE is being configured for a critical system, such as a networked server or a virtual private network (VPN), then this error could have significant implications. However, if the configuration is for a less critical application, the impact may be minimal.

How to Diagnose

To diagnose this issue, follow these steps:

  1. Review Operation Context: Ensure that the IPsec/IKE configuration is being applied in an appropriate context. For example, check whether the configuration is intended for use with a specific protocol or service.
  2. Validate Parameters: Verify that all parameters used in the configuration are correct and supported by the system. This includes checking the encryption algorithms specified.
  3. Confirm Object Types: Ensure that the objects being configured (such as security policies) are of the correct type and intended for use with IPsec/IKE.
  4. Verify Input Data: Check that all input data, including encryption algorithm names or identifiers, are correctly formatted and valid.
  5. Check Limits or Constraints: Confirm that there are no system limits or constraints that could prevent the specified encryption algorithms from being used.

How to Resolve

To resolve this issue, consider the following steps:

  1. Correct Parameter Usage: Ensure that all parameters, including encryption algorithms, are correctly specified and supported by the system.
  2. Adjust Operation Context: If the configuration is intended for a specific context, ensure that it aligns with the requirements of that context.
  3. Restore Data: If data corruption or incorrect settings have led to this error, restore the correct configuration parameters.
  4. Retry Operation with Valid Inputs: After making necessary corrections, attempt to reconfigure IPsec/IKE using valid inputs.

Developer Notes

Developers should ensure that all encryption algorithms used in their applications are supported by the target system and are correctly specified in any configuration files or scripts. Additionally, they should validate input data thoroughly to prevent such errors from occurring.

Related Errors

  • ERROR_IPSEC_IKE_INVALID_CERTIFICATE (0x362F): Indicates an invalid certificate was specified during IPsec/IKE configuration.
  • ERROR_IPSEC_IKE_NO_PRIVATE_KEY (0x3635): Indicates that a private key is required but not provided for the specified encryption algorithm.

FAQ

Q: What does the ERROR_IPSEC_IKE_INVALID_ENCRYPT_ALG error mean?

A: This error indicates that an invalid or unsupported encryption algorithm was specified in the IPsec/IKE configuration.

Q: How can I prevent this error from occurring?

A: Ensure that all encryption algorithms used are supported by your system and correctly specified. Validate input data thoroughly to avoid specifying non-existent or deprecated algorithms.

Q: Can this error affect network security?

A: Yes, if IPsec/IKE is being configured for a critical application, such as securing sensitive data transmission, then this error could impact the overall security of your network.

Summary

The ERROR_IPSEC_IKE_INVALID_ENCRYPT_ALG error indicates that an invalid encryption algorithm was specified in the IPsec/IKE configuration. This can occur due to various reasons, including specifying unsupported algorithms or incorrect parameters. Diagnosing and resolving this issue involves validating input data, ensuring correct parameter usage, and adjusting operation context if necessary.