Revision History - Revision History

The following table shows the revision history for this document.

Section	Revision Summary
05/22/2025 Version 1.8
eFUSE Security Register (FUSE_SEC) Description	Updated Recommend Setting for Bit 0 in Table 1. Added Bit 3 entry to Table 1.
06/24/2024 Version 1.7
Summary	Added recommendation to enforce encryption to important note.
Bitstream Authentication	Clarified the list item about RSA-2048 Authentication.
RSA Authentication	Removed descriptions of using RSA authentication independent of bitstream encryption. Added important note.
Encrypted Bitstream Implementation Overview	Clarified authentication choices in Step 2.
Creating an Encryption Key and Encrypted Bitstream	Changed instances of SSI to 3D IC devices. Clarified note and changed to important note. Added reference to AR 000036543 to important note. Updated NKY file format description to NKY file format for monolithic devices. Added 3D IC NKY file format example. Added monolithic device to vector size example.
Loading the Encryption Key	Updated Figure 1.
BBRAM	Updated Figure 1.
eFUSE	Added important note. Updated Figure 1, Figure 2, Figure 4, and Figure 5.
References	Added reference to Design Advisory 000036039.
02/10/2023 Version 1.6
Updated description for Bits[0:2, 6] in Table 1. Cleaned up Encryption settings code in Creating an Encryption Key and Encrypted Bitstream. Added Table 2.
03/16/2022 Version 1.5
Added security issue description in Summary. Added Design Advisory 76171 in Key Rolling. Updated and added recommended notes in Creating an Encryption Key and Encrypted Bitstream. Added 96 bits description to BITSTREAM.ENCRYPTION.STARTIV0 and BITSTREAM.ENCRYPTION.STARTIVOBFUSCATE in Table 1.
03/26/2021 Version 1.4
Updated FUSE_RSA and FUSE_KEY contents and descriptions in Table 1. Updated Table 1. Updated bits 0-2 in Table 1. Added recommended note and coding in Creating an Encryption Key and Encrypted Bitstream. Updated Possible Value for BITSTREAM.ENCRYPTION.RSAKEYLIFEFRAMES in Table 1. Updated Figure 3. Updated Fallback and IPROG description in Loading the Encrypted Bitstream.
10/12/2018 Version 1.3
Clarified Obfuscated Keys. Changed BITSTREAM.ENCRYPTION.STARTIV0 hex value from 32 bits to 128 bits in Table 1 and in line 14 in the file code snippet. Added content to line 16 in the file code snippet. Clarified eFUSE programming solutions bulleted list under Loading the Loading the Encryption Key. Replaced [Ref 7] under References.
08/15/2018 Version 1.2
Updated eFUSE register descriptions in Table 1. Clarified R_DIS_Key description (bit 0) and added W_DIS_USER_128 (bit 16) in Table 1. Added FUSE_BKS_ENAB (bit 6) and reserved bits 7-31 in Table 1. Clarified write_bitstream properties in Table 1. Added eFUSE Programming General Recommendations.
04/13/2017 Version 1.1
Added reference to Design Advisory 68832 under Summary.
06/02/2016 Version 1.0
Initial release.	N/A

Revision History - Revision History - XAPP1267

Using Encryption and Authentication to Secure an UltraScale/UltraScale+ FPGA Bitstream (XAPP1267)