Send email from iphone/android with public key. Manually unlock with private key

Question

I am needing to know is there a way with iphone and android to send a file encrypted based on a public/private key system?

-- Edit after below post --

Basically I am wanting to: 1. Take a file off an iphone/android 2. Public key encrypt it 3. Email it 4. Manually private key unencrypt it

Thanks

Answer 1

Implement RSA at both side iPhone and Android. You can use openssl to implement RSA at both side. It is peer reviewed and i have used once. And it is working at both side. Generate key pair and send public key to all and keep private key confidential. For example Encrypt file at iPhone side using public key and decrypt the file at Android side with private key .