Encrypting data (HTML)

The following example shows how to use the encrypt method to encrypt data.

function encryptDataBuffer(keyMaterial, stringToEncrypt, algNameString, keysize, ivBuffer) {

    // Input arguments:
    //    keyMaterial.......Buffer that contains random key material (see the GenerateRandom method)
    //    stringToEncrypt...String that contains information to be encrypted
    //    algNameString.....String that contains the name of the symmetric algrorithm to use
    //    keysize...........Requested key size
    //    ivBuffer..........Buffer that contains the initialization buffer (this can be random data or custom defined)

    var encryptedBuffer;

    try {
        // Convert the input string to binary.
        var inputDataBuffer = Windows.Security.Cryptography.CryptographicBuffer.convertStringToBinary(stringToEncrypt, Windows.Security.Cryptography.BinaryStringEncoding.utf8);
        // Open the algorithm provider for the algorithm specified on input.
        var algorithmProvider = Windows.Security.Cryptography.Core.SymmetricKeyAlgorithmProvider.openAlgorithm(algNameString);

        // Check that the requested key size specified on input does not exceed the maximum size supported by the algorithm.
        if (keysize > algorithmProvider.supportedKeyLengths.max) {
            // Handle error.

        // Create a symmetric key.
        var symmetricKey = algorithmProvider.createSymmetricKey(keyMaterial);
        // Check the padding scheme and determine whether the data must be aligned.
        if (algorithmProvider.padding != Windows.Security.Cryptography.Core.CryptographicPadding.block) {
            // Data must be aligned by block size.
            var i = inputDataBuffer.length % algorithmProvider.blockLength;
            if (i > 0) {
               // Handle error.

        // Encrypt the input data.
        encryptedBuffer = Windows.Security.Cryptography.Core.CryptographicEngine.encrypt(symmetricKey, inputDataBuffer, ivBuffer);
    catch (e) {
        // Handle error.
    return encryptedBuffer;

Related topics

Encrypting and decrypting data