Message Digest algorithms in Java Cryptography Architecture

This is the 2nd part of Message Digest algorithms test. I did performance tests on MD5, SHA-1, SHA-256, SHA-384 and SHA-512 in Java Cryptography Architecture (JCA) of Java SE6 against the same file as in 1st part.

Alg. Name	Real Time	User Time	System Time
MD5	0m15.004s	0m9.109s	0m1.344s
SHA-1	0m38.654s	0m35.318s	0m2.036s
SHA-256	0m59.053s	0m56.032s	0m1.784s
SHA-384	1m56.362s	1m53.663s	0m1.364s
SHA-512	1m58.385s	1m53.727s	0m1.484s

The results are quite interesting if compared with the results of md5sum, sha1sum, sha224sum, sha256sum, sha384sum and sha512sum in Ubuntu in 1st part. Basically

• MD5 is comparable in terms of time but with a higher percentage of CPU usage (2X);

• SHA-1 and SHA-256 are much slower (2X);

• SHA-384 and SHA-512 are a bit faster than native implementations.

VoIP bandwidth usage

I think in most countries, it's not a problem to worry about the bandwidth usage of VoIP. But it's obviously not the case here in Australia, most Internet users have download limit or even upload limit. That's why "how much bandwidth is used" becomes an FAQ. There are many bandwidth calculators out there, but here is the statistics from my ATA.

Using G729a codec, the throughput is about 3.6MB/hr in one direction.

Using G711u codec, the throughput is about 28.8MB/hr in one direction.

In my calculation, 1MB = 1,000,000Bytes, which is correct to hard disk manufacturers, Snow Leopard and my ISP.

Message Digest algorithms

I'm doing a home-made backup product that needs to compute checksum of tens of thousands of file. According to Wikipedia, there are quite a number of checksum algorithms.

This product will first base on Linux and some of the checksum utilities are already provided by Ubuntu 9.10. They are md5sum, sha1sum, sha224sum, sha256sum, sha384sum and sha512sum.

In case one day I will port this product to Windows, I also checked MessageDigest of Java Cryptography Architecture (JCA) in Java SE6. It supports MD2, MD5, SHA-1, SHA-256, SHA-384 and SHA-512.

Doing checksum is both CPU and IO intensive. I did a simple performance test today on how much CPU time is needed to compute different checksums (commonly supported by Linux and MessageDigest) of a 723,488,768-byte file.

Alg. Name	Real Time	User Time	System Time
md5sum	0m14.655s	0m4.380s	0m1.300s
sha1sum	0m15.187s	0m12.641s	0m1.764s
sha256sum	0m25.859s	0m23.341s	0m1.656s
sha384sum	2m25.417s	2m23.841s	0m1.432s
sha512sum	2m25.733s	2m23.373s	0m2.116s

Now I have a clear idea of work load of these algorithms. I will do a Java implementation test later to see if I can get similar results.