diff --git a/doc/2013-02-TF5/categories/netarch.txt b/doc/2013-02-TF5/categories/netarch.txt
new file mode 100644
index 0000000..f0f0739
--- /dev/null
+++ b/doc/2013-02-TF5/categories/netarch.txt
@@ -0,0 +1,121 @@
+archaeology
+===========
+
+This is the network archaeology category.  Puzzles center around pulling
+something out of a pcap file.
+ 
+* Base64-encoded plaintext
+
+* Image in pcap of HTTP
+* Image in pcap of SMTP
+* Image in pcap of proto b
+* Image in pcap of out-of-order proto b
+* Image in pcap of out-of-order w/NAK proto b
+
+* Base64-encoded single-byte xor
+* Base64-encoded 4-byte xor
+* Base64-encoded 16-byte xor
+
+* Image in pcap of 1-byte xor out-of-order w/NAK w/filler proto c
+* Image in pcap of proto d, plus a token in the text
+* Image in pcap of proto e, token in the text, and token in zip file
+
+
+proto b
+-------
+
+    01      1 octet         SOH
+    xxxx    2 octets        chunk number (monotonically increasing)
+    xx      1 octet         chunk length
+    ...     <256 octets     up to 255 bytes of data
+    xx      1 octet         checksum (uint8 sum of all data bytes)
+
+    06      1 octet         ACK
+    xxxx    2 octets        chunk number
+    00      1 octet         length 0
+
+    15      1 octet         NAK
+    xxxx    2 octets        chunk number
+    00      1 octet         length 0
+
+    04      1 octet         EOT
+    xxxx    2 octets        chunk number
+    00      1 octet         length 0
+
+
+frob
+----
+
+* srand(0)
+* xor each octet with rand() % argv[1]
+
+
+proto c
+-------
+
+all packets are xored with a per-session randomly-selected key
+
+    offs    len     description
+    ----    ----    -----------
+    00      2       c0 0c
+    02      2       packet length
+    04      1       opcode
+    05      1       00
+    06              data
+
+    opcode  desc    data
+    ------  ----    ---------
+    01      Hello   hostname(cstring), 60 bytes random
+    02      NOP     ∅
+    04      Text    Alice in Wonderland
+    05      Image   part# (2 octets) + data
+    
+
+proto d
+-------
+
+all packets are xored with a per-packet randomly-selected key
+    
+    offs    len     description
+    ----    ----    -----------
+    00      1       00
+    01      1       opcode
+    02      2       packet length
+    04      2       sequence number
+    06              data
+
+    opcode  desc    data
+    ------  ----    ---------
+    01      Hello   hostname(cstring), 60 bytes random
+    02      NOP     ∅
+    04      Text    Alice in Wonderland
+    05      Image   data
+
+
+proto e
+-------
+
+16-byte xor key, applied to entire packet
+
+    offs    len     description
+    ----    ----    -----------
+    00      1       opcode
+    01      1       compression type (0=none, 1=gzip)
+    02      2       packet length
+    04      2       sequence number
+    06              data
+
+    opcode  desc    data
+    ------  ----    ---------
+    01      Hello   hostname(cstring), 60 bytes random
+    02      C2      interactive shell
+    04      fopen   1:mode (0=read, 1=write)
+                    1:fd
+                    n:path
+    05      write   1:fd
+                    4:offset
+                    n:data
+    06      fclose  1:fd
+    08      NOP     ∅
+
+