SSRS Encryption keys lost on two machines at same time.

Question

Two installations of SSRS 2005 on two separate machines in my shop seem to have lost their encryption keys at exactly the same time. These are developer machines with the development edition of SQL Server 2005 running, so I'm hoping that perhaps someone here has an explanation for this. Yesterday, both machines began reporting the error message:

"The report server cannot decrypt the symmetric key used to access sensitive or encrypted data in a report server database. You must either restore a backup key or delete all encrypted content."

These two machines have both "lost" the keys in the past as well and restoring them fixes the problem. However, it seems odd that they both "lost" the keys at the same time and that it seems to happen every two months or so. Does anyone have any ideas why this would be? Here is some information about the installations:

SQL Server Type: SQL Server 2005 Developer Edition

Build Number: 3282 (Cumulative Update 9)

Reporting Services Account: Network Service

Thank you...

Answer 1

What is your windows password change policy? With network service, this should not be relevant though

If the user account or other workstation parameters change (eg install SID), then the keys become invalid. Is someone trying to change the RS service account? Do machine names change?