Kryptomat

Kryptomat - The Cryptography App

With the app Kryptomat any texts can be encrypted. For encryption Kryptomat uses here the RSA algorithm. RSA (Rivest, Shamir, Adleman) is an asymmetric cryptographic method that can be used for both encryption and digital signature. In the asymmetric process, two key pairs are used, in contrast to a symmetric cryptosystem. A public key pair to encrypt data and a secret key pair to decrypt data. Data can be encrypted with the public key pair, which again only the owner of the secret key can decrypt. The communicating parties need therefore not to know a shared secret key, which contributes to increased security of the encryption.
With Kryptomat texts of any length can be encrypted using the RSA method. The strength of the encryption can here be specified during encryption using the bitlength (military standard are 1024 bits) of the primes to be generated. The bitlength is, however, dependent on the available heap memory in Android. Due to this restriction key pairs could be produced with a maximum bitlength of 1023 with the devices tested so far.