ERROR_EFS_ALG_BLOB_TOO_BIG - 6013 (0x177D)
The encryption algorithm used on the source file needs a bigger key buffer than the one on the destination file.
Updated: Feb 21, 2026
Technical Meaning
The ERROR_EFS_ALG_BLOB_TOO_BIG error code, represented by the numeric value 6013 or its hexadecimal equivalent 0x177D, is returned when an encryption operation fails due to insufficient buffer space for the key material required by the encryption algorithm.
Error Details
This error typically occurs during file system operations involving encryption. Specifically, it indicates that the destination file system or volume does not have enough buffer space to accommodate the key material needed by the encryption algorithm applied to the source file. This can happen when attempting to encrypt a file using an algorithm with larger key requirements than those supported by the target file system.
Usage Context
This error is relevant in scenarios where files are being encrypted or decrypted, particularly when dealing with algorithms that require significant amounts of key material. It may occur during operations such as file encryption, directory traversal, or volume-level encryption settings changes.
Developer Interpretation
Developers should interpret this error code to indicate a mismatch between the encryption algorithm's requirements and the available buffer space on the destination system. This could be due to limitations in the target file system, insufficient memory allocation, or unsupported encryption algorithms for the current environment.
Related Errors
ERROR_EFS_ALGORITHM_MISMATCH(6012): Indicates a mismatch between the encryption algorithm used and the supported algorithms by the file system.ERROR_EFS_NOT_ALLOWED_IN_TRANSACTION(5987): Occurs when an operation involving EFS is performed within a transaction context, which is not supported.
FAQ
Q: What causes this error?
A: This error typically occurs due to insufficient buffer space on the destination file system for the key material required by the encryption algorithm used on the source file. It can also be caused by unsupported encryption algorithms or incorrect operation contexts.
Q: How can I resolve this issue?
A: Ensure that the target file system supports the encryption algorithm being used and has sufficient buffer space available. Adjusting the encryption settings or using a different algorithm may resolve the issue.
Summary
The ERROR_EFS_ALG_BLOB_TOO_BIG error code is specific to scenarios where an encryption operation fails due to insufficient key buffer space on the destination file system. Developers should ensure compatibility between the encryption algorithms and the target environment to avoid this error.