optee_example_acipher doesn't work for 4096 keys

[embetrix]

# optee_example_acipher 1024 "some chars"
E/TA:  cmd_enc:100 TEE_AsymmetricEncrypt(10, 0): 0xffff0010
Encrypted buffer: 54 8d 58 66 ef 6f fb 3d 4f 4f 85 a9 5b e5 fc c0 8d b7 de bb f9 e4 f6 bb 5a 60 51 14 67 19 f9 b7 a3 6c 74 63 1d 84 bd 3a ea 17 31 43 0b 64 be 9c 78 89 f0 a1 8a 64 6a f7 a4 bd 75 14 00 e9 f9 43 54 cb 17 59 2d 23 eb bf 70 34 3d ca 88 03 a1 5e 0c fc d3 f0 bd d4 c0 a6 

# optee_example_acipher 2048 "some chars"                                                                                                                                                                                                                                
E/TA:  cmd_enc:100 TEE_AsymmetricEncrypt(10, 0): 0xffff0010
Encrypted buffer: 97 66 33 d2 c6 f6 56 9d ef 56 ed d4 30 3d 5d 16 6a d0 e0 82 01 87 dc 96 0b 7c 97 4a 38 93 f1 84 02 03 61 f3 33 2c 3f a9 06 ee c1 0a fd 81 ab e3 3e 28 d3 c3 02 23 84 8f 54 6a f0 d4 15 d8 80 96 7b 09 df 4b 03 a3 b0 e8 be 9c da 27 bb f2 69 8c 56 6c c4 d9 5a 34 0c 55 

# optee_example_acipher 4096 "some chars"  just hangs!