Like Instagram Name Files

Question

Like Instagram name files, are the file names random? based on some hash? or is there any sense for them? eg

http://distilleryimage2.instagram.com/21a9ca729bf511e2985c22000a1f9ad3_7.jpg

Answer 1

Good answer. The blog post is outdated as their name has changed, but it is probably still based on MD5.

Answer 2

After further verification, I think it's just an MD5 hash or something followed by _ # for image size

Answer 3

Instagram uses an MD5 hash as the base name , followed by an underscore and a number representing the size of the image. Please note that they probably do not just use the contents of the file in their hash, since loading the same image can create a file name conflict, so they will probably add some entropy to their calculations.