Microsoft KB Archive/811886

= PRB: CryptoAPI function Error &quot;Error 0x80090006: Invalid Signature&quot; Connecting to SQL Server by Using SQL Server Authentication =

Article ID: 811886

Article Last Modified on 5/8/2006

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APPLIES TO

 Microsoft SQL Server 2000 Standard Edition, when used with:  Microsoft Windows NT 4.0 Service Pack 5

 Microsoft Windows NT 4.0 Service Pack 6

 Microsoft Windows NT 4.0 Service Pack 6a

 Microsoft Windows 2000 Server</li></ul>

 Microsoft Windows Server 2003, Standard Edition (32-bit x86)</li></ul> </li></ul>

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SYMPTOMS
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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CAUSE
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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WORKAROUND
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:

Internet Explorer High Encryption Pack

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