XOR encryption in assembly is three operations: open a file, XOR each byte against a key in a tight loop, write the output. The fixed-key version is eight instructions per iteration; the rolling-key version adds one — add r15b, 0x11 — which updates the key every cycle and wraps automatically at 0xFF because r15b is 8-bit. Both versions decrypt with the same code. The real lesson is a pointer bug that every assembly programmer hits: mov rdx, [buffer] dereferences the label, turning file data into a memory address and segfaulting; lea rdx, [buffer] takes the address itself.
SHA-256 output distribution is not featureless. CDP projects each 64-hex-digit output to a scalar weight W ∈ [434,555] across 961 classes, revealing a Cycle-1 (476↔438 fixed point), an 8-node Cycle-2, and strongly asymmetric basin topology. The 38.6x scalar pre-filter achieves zero false negatives. Compound triple constraint delivers 42.55x rainbow chain speedup — 16.6x beyond the published literature best of 2.56x. OpenCL implementation included.
Sending an RFC 9114 §4.1 trailer HEADERS frame to production HTTP/3 infrastructure triggers state machine failures across two independent CDN edge implementations and the quiche client library. Server-side: 60-second goroutine hang (CDN-A) and 12,200ms QPACK decoder stall with 24.9× worker amplification (CDN-B). Client-side: permanent zombie stream leak in quiche driving Network Service memory from 6 MB to 339 MB before OOM. All three share the same root cause: the second HEADERS frame on a request stream reaches a code path with no defined handler. The threat model inversion — server pushing a malformed trailer toward client — transforms a server-side bug class into a drive-by browser memory exhaustion attack.
A malformed trailer HEADERS frame (END_STREAM=0) on a WebTransport CONNECT stream leaves quiche’s stream state machine permanently stuck: trailers_decompressed_=true but fin_received()=false, causing IsDoneReading() to return false forever. The stream is never removed from stream_map_, ShouldKeepConnectionAlive() holds the QUIC connection open, and Edge sends PING keepalives every ~15s indefinitely. A single webpage can open thousands of these zombie connections with no server-side limit, exhausting Network Service memory and crashing the browser. Both MSRC and Chrome VRP declined to track as security issues.
On Windows ROCm 7.14 + RX 9070 XT (gfx1201/RDNA 4), any HIP kernel dispatch crashes with STATUS_ACCESS_VIOLATION. WinDbg live debugging reveals a garbage pointer in the ROCprofiler callback linked list inside hipProfilerRegisterChunkCallbackExt. A first patch targeting hipLaunchKernel+0x85 stopped the crash but silenced all GPU compute — tensors returned zero. The correct fix patches hipProfilerRegisterChunkCallbackExt itself to immediately return 0, leaving kernel dispatch intact.
Static analysis of a Go-based Linux RAT (Warp/Wraith family, SHA256: 3bfc4394…) that manipulates its ELF structure to evade analysis tools. Three structural anomalies — section header table past EOF, oversized PT_LOAD segment, and dynamic linking on a Go binary — produce an immediate malicious verdict before any disassembly runs. String analysis identifies SSH/SFTP credential harvesting, /bin/systemd-worker process masquerading, and a related 736KB variant (e097c852…) with embedded coinminer payload. Detected via static ELF header inspection alone, no sandbox required.
