As far as I'm aware, no.
You could, of course just use HTTPS.
Some sort of custom encryption might be inline here.
One that I came up with goes something like this:
Have a few charts that [randomly] map different numbers to each other (1=54,30=255 etc) no number may be repeated.
Both parties must have at least two charts (they need the same charts), preferably more.
In the message, you supply, near the start, which chart is being used. Then for each ASCII character in the string, choose 2 numbers from the first side of the chart, that, when
averaged, will equal the ASCII value of the character you want to encrypt. You then use the 2 ASCII characters in place of the original. That probably makes no sense though
It's unencrypted something like this:
Get Chart that is being used
take first 2 chars
Get ASCII values of them
take the average of those 2 values
Check that ASCII value against the chart
get the value on the other side
turn in back into ASCII
Goto next 2 chars
For more encryption, use multiple charts.
ie.
take first 2 chars
Get ASCII values of them
Get the ASCII values on the other side (from first chart)
take the average of those 2 values
Check that ASCII value against the second chart
get the value on the other side
turn in back into ASCII
Goto next 2 chars
The benefits of this, is that it's virtually unbreakable!
Because each letter has thousands of possibilities, you can use a different one each time. This means that there's NO recognizable pattern.
I'm quite happy with this cipher
I came up with it when I was about 10. I'm surprised I still remember it all these years
Hope that makes sense
Of course, you could just use the old fashioned
Simple Substitution Cipher
which should be enough to discourage people trying to crack it
