from the droidcon UK 2012 conference

1. droidcon UK 2012
Beaming Data to
Devices with
NFC
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2. Lodnon 2012 Oimplycs
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3. Jimmy B.
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4. Q
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5. NFC: Good for Spies
● Near Field Communication
● Configuration-Free
– No pairing for a connection
● Short Distance
– Only a few centimeters
– Less chance of interception by nefarious no-
good-niks
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6. Secret Agent Man Sample App
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7. NFC: Dead ASCII Drop
● NFC Tag
– Rewriteable or WORM
– “Hidden in plain sight” (e.g., behind poster)
– Source writes information to tag
– Agent reads information from tag, cleans up
● Delete data
● Remove tag
● Destroy building
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8. NFC: Tag Limits
● Limited Capacity
– 1KB on down
– Compression, encryption will tend to offset one
another
● Public
– Could be found, read, confiscated
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9. Beam: Up Close... And Personal!
● Android Beam
– NFC P2P
– Put devices back to back
– One sends, other receives
● Benefits
– Devices in hand at all times
– Capacity
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10. AAR: Ahoy, Matey!
● Android Application Record
– Identifies an app that should be able to consume
this Beam
– If nothing seems capable of handling the Beam,
Android will use AAR record to launch Play Store
– Issue: MI6 apps not usually on Play Store
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11. Beam: Performance Anxiety
● NFC Transfer Rate Limited
– Theoretically 424 kbps
– In practice, not that fast
● Net: Still Not Good for Large Transfers
– Capacity gated by time to transfer
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12. Uri Beaming: Size Matters
● Automatic Bluetooth Bootstrapping
– NFC to pair devices automatically
– Transfer files, designated by Uri values, to the
other device
● Benefits
– Higher transfer rate
– Longer range
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13. Uri Beaming: A Quantum of Issues
● Android 4.1+
● OS Receives the File
– Not your code
– No control over where gets written
● Greater Interception Risk
– Extended range is blessing and curse
– Encrypt the data if needed
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14. Beam: Push Uris Are Not Enough
● May Wish to “Roll Your Own”
– Use NFC to bootstrap communications handled
over other networks with other protocols
● Possibilities
– Bluetooth
– Internet
– WiFi Direct
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15. Speaker Contact
Information
Sample
SlideShare App
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