Launcher gives up at downloading jars

Please attach the complete output of the "Launcher Log"

Where do launcher logs get saved?

Nowhere , but simply restart the Launcher , after failing to download mark all the text and paste it here.

Alright, sorry if I took long, but I attached the file.

Encryption cannot be set up

[19:26:55 WARN]: Couldn't download https://libraries.minecraft.net/com/mojang/realms/1.7.4/realms-1.7.4.jar for job 'Version & Libraries'
java.lang.NoClassDefFoundError: Could not initialize class javax.crypto.JceSecurity
	at javax.crypto.Cipher.getInstance(Cipher.java:499) ~[?:1.7.0_71]
	at sun.security.ssl.JsseJce.getCipher(Unknown Source) ~[?:1.7.0_71]
	at sun.security.ssl.CipherBox.<init>(Unknown Source) ~[?:1.7.0_71]
	at sun.security.ssl.CipherBox.newCipherBox(Unknown Source) ~[?:1.7.0_71]
	at sun.security.ssl.CipherSuite$BulkCipher.newCipher(Unknown Source) ~[?:1.7.0_71]
	at sun.security.ssl.CipherSuite$BulkCipher.isAvailable(Unknown Source) ~[?:1.7.0_71]
	at sun.security.ssl.CipherSuite$BulkCipher.isAvailable(Unknown Source) ~[?:1.7.0_71]
	at sun.security.ssl.CipherSuite.isAvailable(Unknown Source) ~[?:1.7.0_71]
	at sun.security.ssl.SSLContextImpl.getApplicableCipherSuiteList(Unknown Source) ~[?:1.7.0_71]
	at sun.security.ssl.SSLContextImpl.getDefaultCipherSuiteList(Unknown Source) ~[?:1.7.0_71]
	at sun.security.ssl.SSLSocketImpl.init(Unknown Source) ~[?:1.7.0_71]
	at sun.security.ssl.SSLSocketImpl.<init>(Unknown Source) ~[?:1.7.0_71]
	at sun.security.ssl.SSLSocketFactoryImpl.createSocket(Unknown Source) ~[?:1.7.0_71]
	at sun.net.www.protocol.https.HttpsClient.afterConnect(Unknown Source) ~[?:1.7.0_71]
	at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source) ~[?:1.7.0_71]
	at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source) ~[?:1.7.0_71]
	at java.net.HttpURLConnection.getResponseCode(Unknown Source) ~[?:1.7.0_71]
	at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(Unknown Source) ~[?:1.7.0_71]
	at com.mojang.launcher.updater.download.ChecksummedDownloadable.download(ChecksummedDownloadable.java:49) ~[launcher_mcpatched.jar:?]
	at com.mojang.launcher.updater.download.DownloadJob.popAndDownload(DownloadJob.java:109) [launcher_mcpatched.jar:?]
	at com.mojang.launcher.updater.download.DownloadJob.access$000(DownloadJob.java:12) [launcher_mcpatched.jar:?]
	at com.mojang.launcher.updater.download.DownloadJob$1.run(DownloadJob.java:86) [launcher_mcpatched.jar:?]
	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.7.0_71]
	at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.7.0_71]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:1.7.0_71]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?:1.7.0_71]
	at java.lang.Thread.run(Unknown Source) [?:1.7.0_71]

Duplicate of MC-21013