Metadata in PDF files can be stored in at least two places:
- the Info Dictionary, a limited set of key/value pairs
- XMP packets, which contain RDF statements expressed as XML
CoelacanthusHex
/ latency.txt
Created
May 1, 2020 15:16
— forked from jboner/latency.txt
Latency Numbers Every Programmer Should Know
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| Latency Comparison Numbers (~2012) | |
| ---------------------------------- | |
| L1 cache reference 0.5 ns | |
| Branch mispredict 5 ns | |
| L2 cache reference 7 ns 14x L1 cache | |
| Mutex lock/unlock 25 ns | |
| Main memory reference 100 ns 20x L2 cache, 200x L1 cache | |
| Compress 1K bytes with Zippy 3,000 ns 3 us | |
| Send 1K bytes over 1 Gbps network 10,000 ns 10 us | |
| Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD |
CoelacanthusHex
/ README.md
Created
July 9, 2020 04:53
— forked from hubgit/README.md
Remove metadata from a PDF file, using exiftool and qpdf. Note that embedded objects may still contain metadata.
CoelacanthusHex
/ gist:5459c4b58416b82f6ec9af3d886504e3
Created
November 4, 2020 06:22
— forked from atoponce/gist:07d8d4c833873be2f68c34f9afc5a78a
Cryptographic Best Practices
Putting cryptographic primitives together is a lot like putting a jigsaw puzzle together, where all the pieces are cut exactly the same way, but there is only one correct solution. Thankfully, there are some projects out there that are working hard to make sure developers are getting it right.
The following advice comes from years of research from leading security researchers, developers, and cryptographers. This Gist was [forked from Thomas Ptacek's Gist][1] to be more readable. Additions have been added from