diff --git a/book/source/diag/signature_packet.png b/book/source/diag/signature_packet.png new file mode 100644 index 0000000..1d557f7 Binary files /dev/null and b/book/source/diag/signature_packet.png differ diff --git a/book/source/diag/types_of_signatures.png b/book/source/diag/types_of_signatures.png index 8eef40d..44b7a15 100644 Binary files a/book/source/diag/types_of_signatures.png and b/book/source/diag/types_of_signatures.png differ