A friend oracle database dmp backup is encrypted, with the suffix: .DMP.voyager. Through analysis, it is found that the file is encrypted about 2M.

It can be seen here that the dmp file is exported in expdp mode (expdp is essentially stored in xml mode, exp is stored in direct binary mode), and the situation of the recoverable table is analyzed by tools.
Analyze the dmp file with a tool

CPFL> OPEN F:\BaiduNetdisk\KINGDEE85GH_2020-03-17.DMP.voyager
TABLE_NAME START_POS DATA_BYTE
-------------------------------------------------- --------------- ---------------
KINGDEE85GH.T_WFD_PROCESSDEF 116300288 648396035
KINGDEE85GH.T_DYN_DYNAMICCONFIGURE 864710656 181453794
KINGDEE85GH.T_RPTS_STORAGEFILEDATA 1078767616 21548951
KINGDEE85GH.T_BOT_RULESEGMENT 1100324864 10372516
KINGDEE85GH.T_LOG_APP 1110712320 12603573
KINGDEE85GH.T_PM_PERMITEM 1123336192 7282412
KINGDEE85GH.T_PM_USERORGPERM 1130635264 6692320
KINGDEE85GH.T_DYN_APPSOLUTION 1137336320 801697
KINGDEE85GH.T_PM_MAINMENUITEM 1138155520 3573943
KINGDEE85GH.T_PM_PERMUIGROUP 1141751808 2159245
KINGDEE85GH.T_SYS_ENTITYREF 1143922688 4183869
KINGDEE85GH.T_PM_ROLEPERM 1148116992 2758960
KINGDEE85GH.T_BAS_SYSMENUITEM 1150885888 3304627
KINGDEE85GH.T_JP_PAGE 1154211840 3019174
…………
KINGDEE85GH.T_XT_CHECKTIME 1212776448 41
KINGDEE85GH.T_XT_SYNCHTIME 1212784640 41
SYSTEM.SYS_EXPORT_SCHEMA_02 1212792832 215423380
-------------------------------------------------- --------------- ---------------
Scanned Find 895 segments.

Through this, you can basically determine that more than 100 M data have been lost, and other data can theoretically be recovered.
Create a user

SQL> create user KINGDEE85GHidentified by oracle;

User created.

SQL> grant dba to KINGDEE85GH;

Grant succeeded.

unexpdp data (automatic table creation and import data)

CPFL> unexpdp table KINGDEE85GH.T_WFD_PROCESSDEF

unexpdp table: KINGDEE85GH.T_WFD_PROCESSDEF storage (START_POSITION:116300288 DATA_BYTE:748396035)
824 rows unexpdp