> I remember seeing somewhere a suggestion that Firebird could already support page-level encryption by two user-defined functions to encode the page before writing it and decode it after reading. I guess this is the way to go without losing any engine functionality. Please if anyone has better memories or actual knowledge, comment on this.

Yes, this code in engine is defined-out with macro

/* dimitr: just uncomment the following line to use this feature.
Requires support from the PIO modules. Only Win32 is 100% ready
for this so far. Note that the database encryption code in the
PIO layer seems to be incompatible with the SUPERSERVER_V2 code.
2003.02.09 */
//#define ISC_DATABASE_ENCRYPTION

External plugin is required for encryption and key is provided within
DPB.

SY, SD.