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PRB: CryptoAPI function Error "Error 0x80090006: Invalid Signature" Connecting to SQL Server by Using SQL Server Authentication

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When you use SQL Server Authentication to connect to SQL Server, you may receive the following error message:
Server: Msg 552, Level 16, State 1
[Microsoft][ODBC SQL Server Driver][SQL Server]CryptoAPI function 'CryptAcquireContext' failed. Error 0x80090006:
Invalid Signature.
Additionally, in the About Internet Explorer dialog box, there is no Cipher Strength value or the value is 0-bit.

Note To view the Cipher Strength value, in Microsoft Internet Explorer, click About Internet Explorer on the Help menu.

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This behavior may occur if any of the following files are missing, damaged, or the incorrect version:
  • Ndiswan.sys
  • Ntlmssps.dll
  • Schannel.dll
  • Security.dll
  • Rsabase.dll
  • Rsaenh.dll
The incorrect versions may exist when you install both 128-bit encryption and 40-bit encryption on the operating system.

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To work around this problem, reinstall Microsoft Internet Explorer to have the same version of the security and encryption DLLs.

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More information

To authenticate SQL Server login, SQL Server uses the Microsoft Windows NT CryptoAPI functions. When a SQL Server login is created, the password is encrypted with the CryptoAPI functions. The encrypted password is stored in the SQL Server system table. When you use SQL Authentication to connect to SQL Server, the password in the connection string is encrypted and compared with the password that is stored in the system table. The connection is permitted only when both passwords match.

For additional information about Internet Explorer High Encryption Pack, visit the following Microsoft Web site:

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For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
321459 PRB: The CryptoAPI Function Generates an Error When You Try to Connect to an Instance of SQL Server 2000
216270 128-Bit Encryption Upgrade May Not Work with Service Pack 4
176820 Differences Between 128-bit and 40-bit versions of Service Pack 3 and Service Pack 4
322051 Programs May Not Connect to the Server with Mismatched Security DLLs in Windows NT 4.0
261328 Cipher Strength Appears as 0-Bit in Internet Explorer
195833 How to Upgrade Internet Explorer to 128-Bit Encryption

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Keywords: KB811886, kbprb, kberrmsg

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Article Info
Article ID : 811886
Revision : 8
Created on : 5/8/2006
Published on : 5/8/2006
Exists online : False
Views : 432