The development of efficient data encryption to ensure high security of information transmission has long been a popular research subject. Because electrocardiogram (ECG) signals vary from person to person, and can be used as a new tool for biometric recognition. This study introduces an individual feature of ECG with chaotic Henon and logistic maps for personalized cryptography. This study also develops an encryption algorithm based on the chaos theory to generate initial keys for chaotic logistic and Henon maps. The proposed personalized encryption system uses a convenient handheld device to collect ECG signals from the user. High quality randomness in ECG signals results in a widely expanded key space, making it an ideal key generator for personalized data encryption. The experiments reported in this study demonstrate the use of this approach in encrypting texts and images, and applied of the proposed approach to secure communications.