JavaScrypt runs entirely in your browser--nothing is sent to any Web site when you use it. You can, if you wish, download JavaScrypt to your own computer and use it when not connected to the Internet.
JavaScrypt's encryption facilities use the Advanced Encryption Standard (AES) adopted by the United States as Federal Information Processing Standard 197. AES supports key lengths of 128, 192, and 256 bits; JavaScrypt uses 256 bit keys exclusively.
Encrypted message sample
##### Encrypted: decrypt with http://www.fourmilab.ch/javascrypt/ ZZZZZ GLGXE NPCED CUGUT PFDLU WGJRU TABPW OJJRG ICUQE KSCRC ECTEM GRVVJ ENJTA MFUDU BLGMK IXKKG VAOQL MTIUR ORNXP WPFAB WMIKV VPDWB ITKTX QCBCM RMBAE UDVEB OSRZZ YYYYY ##### End encrypted message
Dyspneic cushats lawines. Carnify resalute fluidics dimmest dioceses ologist shop. Aucubas popedoms gardenia bustling, maremme. Bowleg imparks restored praus breaths, fabling. Fidges hosen, sparker disunity chics. Redbait met gestapo ixtle busses. Icily.
The key is Fnord.